Author: Carl Stalhood

EUC Weekly Digest – September 9, 2017

Last Modified: Nov 7, 2020 @ 6:34 am

2 Comments

Here are some EUC items I found interesting last week. For more immediate updates, follow me at http://twitter.com/cstalhood.

For a list of updates at carlstalhood.com, see the Detailed Change Log.

 

XenApp/XenDesktop

App Layering (Unidesk)

StoreFront

NetScaler

NetScaler MAS

NetScaler Gateway

XenMobile

ShareFile

Other

NetScaler SDX 12 / Citrix ADC SDX 12.1

Last Modified: Dec 21, 2018 @ 5:49 pm

65 Comments

Navigation

Change Log

  • 2018 Dec 21 – updated screenshots for SDX 12.1
  • 2018 Mar 20 – updated upgrade instructions for 12.0 build 57
  • 2018 Mar 20 – in Provision VPX section, added Crypto Units info

Overview

Citrix CTX226732 Introduction to Citrix NetScaler SDX.

Citrix ADC SDX is normal Citrix ADC hardware, but runs XenServer hypervisor, and several virtual machines that are listed below:

  • Service VM (aka Management Service, aka SVM) – every SDX comes with this Virtual Machine. This VM enables the SDX Administrator to create additional VMs on XenServer. It’s analogous to vCenter, except each SDX has its own SVM.
    • It’s not possible to build this VM yourself. If it something happens to it, your only choice is to do a factory reset on the physical appliance, which deletes all local virtual machines, and recreates the Service VM.
    • Each Service VM only manages the VMs on the local SDX. Each SDX has its own Service VM. To manage multiple SDXs, use Citrix Application Delivery Management (ADM).
    • XenServer on SDX is a special build. Do not attempt to directly upgrade XenServer, patch XenServer, configure XenServer, etc. Instead, all upgrades and configurations should be performed by the Service VM.
  • Citrix ADC VPX Instances – you create one or more Citrix ADC instances on top of XenServer.
    • The number of Citrix ADC instances you can create is limited by your SDX license. Most models let you buy more instances.
    • The physical resources (CPU, Memory, NICs, SSL Chips, FIPS HSM) of the SDX are partitioned to the different instances.
    • The amount of bandwidth (throughput) available to the VPX instances depends on your license. For example, the 14040 SDX license gives you 40 Gbps of throughput, which is partitioned across the instances.
    • The Citrix ADC instances are created from a normal XenServer .xva template.
    • Each VPX has its own NSIP. Once the VPX is provisioned, you connect to the NSIP, and configure it like a normal Citrix ADC .

If the top left of the window says SDX, then you are logged into the Management Service (aka Service VM, aka SVM). If it says VPX, then you are logged into an instance.

High Availability – Citrix ADC SDX does not have any High Availability capability at the XenServer or SVM layer. In other words, every SDX is completely standalone. To achieve HA, you create Citrix ADC VPX instances on two separate SDXs, and pair the VPX instances in the normal fashion. See Citrix ADC High Availability.

Why Citrix ADC VPX on top of SDX instead of normal hypervisors?

  • VPX on SDX gets physical access to SSL chips. These SSL ASICs are not available on normal hypervisors. SSL Chips provide significantly higher SSL throughput than normal hypervisors.
  • VPX on SDX gets SR-IOV access to the Network interfaces. This enables full 40 Gbps throughput to a single VM.
  • The SDX NICs can filter VLANs to different instances, thus ensuring that VPX instances cannot cross security boundaries by adding the wrong VLANs.
  • Some SDXs have Hardware Security Modules (HSM) for FIPS compliance. The VPXs on SDX can utilize this hardware security resource.

SDX Networking

  • Management port – Every SDX has a 0/1 port.
    • The SVM and XenServer management IP are on this NIC.
    • You need a minimum of two IPs on a management network connected to the 0/1 port.
    • SVM and XenServer cannot use any of the data ports for management.
  • LOM port – Every SDX has a Lights Out Management (LOM) port.
    • The LOM port gives you out-of-band console access to XenServer. Once you’re on XenServer, you can use Xen commands to see the SVM console, and/or VPX consoles.
  • Data ports – The remaining interfaces can be aggregated into port channels. Port channels are configured at XenServer, and not from inside the VPXs. Use the Service VM to create channels, and then connect the VPXs to the channels.
  • VPX networking – When VPXs are created, you specify which physical ports to connect the virtual machine to.
    • If you want the VPX NSIP to be on the same subnet as SVM and XenServer, then connect the VPX to 0/1.
    • Connect the VPX to one or more LA/x interfaces (port channels).
    • Once the VPX is created, log into it, and create VLAN objects in the normal fashion. VLAN tagging is handled by the VPX, not XenServer.
    • On SVM, when creating the VPX instance, you can specify a list of allowed VLANs. The VPX administrator is only allowed to add VLANs that are in this list.
  • SVM to NSIP – SVM must be able to communicate with every VPX NSIP. If VPX NSIP is on a different subnet than SVM, then ensure that routing/firewall allows this connection.

LOM IP Configuration

There are two ways to set the IP address of the Lights Out Module (LOM):

  • ipmitool from the Citrix ADC SDX XenServer command line
    • For MPX, you can run ipmitool from the BSD shell.
  • Crossover Ethernet cable from a laptop with an IP address in the 192.168.1.0 network.

Ipmitool Method:

  1. For SDX, SSH to the XenServer IP address (not the Service VM IP).
    • For MPX, SSH to the Citrix ADC NSIP.
  2. Default XenServer credentials are root/nsroot.
    1. Default MPX credentials are nsroot/nsroot.
  3. If MPX, run shell. XenServer is already in the shell.
  4. Run the following: 
    ipmitool lan set 1 ipaddr x.x.x.x
ipmitool lan set 1 netmask 255.255.255.0
ipmitool lan set 1 defgw ipaddr x.x.x.x

  5. You should now be able to connect to the LOM using a browser.

Laptop method:

  1. Configure a laptop with static IP address 192.168.1.10 and connect it to the Lights Out Module port.
  2. In a Web browser, type the IP address of the LOM port. For initial configuration, type the LOM port’s default address: http://192.168.1.3
  3. In the User Name and Password boxes, type the administrator credentials. The default username and password are nsroot/nsroot.
  4. In the Menu bar, click Configuration, and then click Network.
  5. Under Options, click Network, and type values for the following parameters:
    1. IP Address—The IP address of the LOM port.
    2. Subnet Mask—The mask used to define the subnet of the LOM port.
    3. Default Gateway—The IP address of the router that connects the appliance to the network.
  6. Click Save.
  7. Disconnect the laptop, and instead connect a cable from a switch to the Lights Out Module.

LOM Firmware Upgrade

The LOM firmware at https://www.citrix.com/downloads/netscaler-adc/components/lom-firmware-upgrade differs depending on the hardware platform. The LOM firmware for the 8000 series is different than the 11000 series and the 14000 series. Do not mix them up.

SDX 12.0 build 57 and newer automatically upgrade the LOM firmware when you upgrade the SDX firmware.

Citrix ADC MPX has a new method for updating LOM as detailed at CTX218264 How to Upgrade the LOM Firmware on Any NetScaler MPX Platform

For SDX firmware older than 12.0 build 57, update the LOM firmware separately:

  1. Determine which firmware level you are currently running. You can point your browser to the LOM and login to the see the firmware level. Or you can run ipmitool mc info from the XenServer shell.
  2. If your LOM firmware is older than 3.0.2, follow the instructions at http://support.citrix.com/article/CTX137970 to upgrade the firmware.
  3. If your LOM firmware is version 3.02 or later, follow the instructions at http://support.citrix.com/article/CTX140270 to upgrade the firmware. This procedure is shown below.
  4. Now that the firmware is version 3.0.2 or later, you can upgrade to 3.39. Click the Maintenance menu and then click Firmware Update.
  5. On the right, click Enter Update Mode.
  6. Click OK when prompted to enter update mode.
  7. Click Choose File, and browse to the extracted bin file.
  8. After the file is uploaded, click Upload Firmware.
  9. Click Start Upgrade.
  10. The Upgrade progress will be displayed.
  11. After upgrade is complete, click OK to acknowledge the 1 minute message.
  12. The LOM will reboot.
  13. After the reboot, login and notice that the LOM firmware is now 3.39.

SDX IP Configuration

Default IP for Management Service is 192.168.100.1/16 bound to interface 0/1. Use a laptop with crossover cable to reconfigure the IP. Point your browser to http://192.168.100.1. Default login is nsroot/nsroot.

Default IP for XenServer is 192.168.100.2/16. Default login is root/nsroot.

  • There should be no need to connect to XenServer directly. Instead, all XenServer configuration (e.g. create new VM) is performed through the Management Service (SVM).
  • When you set the SVM’s IP Address, there is also a field to also set the XenServer IP address. XenServer IP and Management Service IP must be on the same subnet.

To change the XenServer IP, make the change through the SVM as detailed below:

  1. Point a browser to http://192.168.100.1, and login as nsroot/nsroot.
  2. When you first login to the SDX Management Service, the Welcome! Wizard appears. Click the first row for Management Network.
  3. Configure the IP addresses.
    1. Appliance Management IP = SVM (Management Service). This is the IP you’ll normally use to manage SDX.
    2. Application supportability IP = XenServer. You’ll almost never connect to this IP.
    3. The bottom has an Additional DNS checkbox that lets you enter more DNS servers.
    4. You can change the nsroot password at this time, or change it later after LDAP is configured.
  4. Click Done.
  5. Click the System Settings box.
  6. Enter a Host Name.
  7. Select the time zone, and click Continue.
  8. Click the Licenses box.
  9. Click Add License File.
  10. Allocate Citrix ADC SDX licenses normally.
    1. The SDX license defines the number of instances you can create.
    2. It also defines the amount of throughput available to the instances.
    3. The SDX license is allocated to ANY, which means you can use the same license on all SDX hardware, assuming all of them are purchased with the same license model.
  11. Click Browse to upload the license file. After uploading, click Finish and it should apply automatically.
  12. Or you can click Apply Licenses.
  13. Then click Continue.

Another way to change the Management Service IP address is through the serial port. This is actually the XenServer Dom0 console. Once logged in to XenServer, run ssh 169.254.0.10 to access the Management Service virtual machine. Then follow instructions at http://support.citrix.com/article/CTX130496 to change the IP.

The console of the Management Service virtual machine can be reached by running the following command in the XenServer Dom0 shell (SSH or console):

xe vm-list params=name-label,dom-id name-label="Management Service VM"

Then run /usr/lib64/xen/bin/xenconsole <dom-id>

SDX Platform Software Bundle

If your Citrix ADC SDX is not version 11 or newer, and if your Citrix ADC SDX is running 10.5 build 57 or later, then do the following:

  1. Go to Management Service > Software Images, and upload the Single Bundle for 12.0 or 12.1. The single bundle is around 1.5 GB.
  2. On the left, click System.
  3. On the right, click Upgrade Management Service. Select the Single Bundle upgrade file you already uploaded.
  4. Management Service will upgrade and reboot. A few minutes after that, XenServer will be upgraded. Be patient as there’s no notification that the box will reboot again.

Starting with SDX 11.0, all updates are bundled together and installed at once.

  1. Make sure your Management Service (SVM) is running SDX 10.5 build 57 or newer.
  2. Download the latest SDX Platform Software bundle from Downloads > Citrix ADC > Release 12.1 (or 12.0) > Service Delivery Appliances.

  3. Login to the SDX Management Service, and go to Configuration > System.
  4. On the right, in the right column, click Upgrade Appliance.
  5. Browse to the build-sdx-12.1.tgz software bundle, and click OK.
  6. It should show you the estimated installation time.
  7. Check boxes next to the instances that need configs saved.
  8. Click Upgrade.
  9. Click Yes to continue with the upgrade.
  10. The Management Service displays installation progress. It will take a while.
  11. Once the upgrade is complete, click Login.

  12. If you click the Configuration tab, the Information page will be displayed showing the version of XenServer, Management Service (Build), etc.

FIPS

If your SDX is a FIPS appliance, see Citrix Blog Post Meet Security Compliance and Be Scalable with NetScaler FIPS SDX for detailed HSM setup instructions:

  1. Zeroize the HSM
  2. Upgrade HSM firmware
  3. Create HSM partitions
  4. Create Citrix ADC instance and attach HSM partition:
    • Only one CPU core
  5. From inside Citrix ADC instance:
    1. Reset FIPS
    2. Initialize FIPS
    3. Create FIPS Key
    4. Create HA Pair and synchronize FIPS

DNS Servers

Older versions of SDX only let you enter one DNS server. To add more, do the following:

  1. In the Management Service, on the left, click System.
  2. On the right, click Network Configuration.
  3. On the bottom, there’s a checkbox for Additional DNS that lets you put in more DNS servers.
  4. Click OK when done.

Management Service NTP

  1. On the Configuration tab, in the navigation pane, expand System, and then click NTP Servers.
  2. To add a new NTP server, in the right pane, click Add.
  3. In the Create NTP Server dialog box, enter the NTP server name (e.g. pool.ntp.org), and click Create.
  4. Click Yes when prompted to restart NTP Synchronization.
  5. In the right pane, click NTP Synchronization.
  6. In the NTP Synchronization dialog box, select Enable NTP Sync. Click OK.
  7. Click Yes when asked to restart the Management Service. This only restarts the SVM. Other instances on the same box won’t be affected.

Licensing

If you haven’t already licensed your SDX, you can upload a license file to the SDX appliance.

  1. Login to http://mycitrix.com and go to Manage Licenses.
  2. In the New Licenses section, find a Citrix ADC SDX license, and allocate it. There is no need to specify a hostname. You can use the same license file on multiple SDX appliances.

  3. On the SDX Configuration tab, in the navigation pane, expand System, and then click Licenses.
  4. In the right pane, click Add License File.
  5. Click Browse and upload the allocated license file.
  6. Click Finish.
  7. If you refresh your browser, the number shown on the top left of the window will indicate your licensed model number.

Management Service Alerting

Syslog

  1. On the Configuration tab, expand System > Auditing, and click Syslog Servers.
  2. In the right pane, click the Add button.

    1. Enter a name for the Syslog server.
    2. Enter the IP address of the Syslog server.
    3. Change the Choose Log Level section to Custom, and select log levels.
  3. Click Create.
  4. On the right is Syslog Parameters.
  5. You can configure the Date Format and Time Zone. Click OK.

Mail Notification

  1. On the Configuration tab, expand System > Notifications, and click Email.
  2. In the right pane, on the Email Servers tab, click Add.
  3. Enter the DNS name of the mail server, and click Create.
  4. In the right pane, switch to the tab named Email Distribution List, and click Add.
  5. In the Create Email Distribution List page:
    1. Enter a name for the mail profile.
    2. Select the Email Server to use.
    3. Enter the destination email address (distribution list).
  6. Click Create.
  7. SDX 12.1 and newer has a Test button for the Distribution List.

System SNMP

  1. Go to System > SNMP.
  2. On the right, click Configure SNMP MIB.
  3. Enter asset information, and click OK. Your SNMP management software will read this information.
  4. Under the SNMP node, configure normal SNMP including: Trap Destinations, Managers, Alarms, etc.

  5. MIBs can be downloaded from the Downloads tab.

Instance SNMP

  1. The instances will send SNMP traps to the Service VM. To get alerted for these traps, in the Configuration page, in the navigation pane, expand Citrix ADC (or NetScaler), expand Events, and click Event Rules.
  2. On the right, click Add.

    1. Give the rule a name.
    2. Move the Major and Critical severities to the right.
    3. Scroll down.
    4. For the other sections, if you don’t configure anything then you will receive alerts for all of the devices, categories, and failure objects. If you configure any of them, then only the configured entities will be alerted.
    5. Scroll down.
    6. Click Save.
  3. Select an Email Distribution List, and click Done.

Management Service nsroot Password and AAA

Change nsroot password

  1. On the Configuration tab, in the navigation pane, expand System, expand User Administration, and then click Users.
  2. On the right, in the Users pane, right-click the nsroot user account, and then click Edit.
  3. In the Configure System User dialog box, check the box next to Change Password.
  4. In Password and Confirm Password, enter the password of your choice.
  5. Scroll down and click OK.

AAA Authentication

To enable LDAP authentication for the Service VM:

  1. Go to Configuration > System > Authentication > LDAP.
  2. In the right pane, click Add.
  3. This is configured identically to Citrix ADC.
    1. Enter a Load Balancing VIP for LDAP servers.
    2. Change the Security Type to SSL, and Port to 636.
    3. Scroll down.
    4. Note: if you want to Validate LDAP Certificate, then there are special instructions for installing the root certificate on the SVM. See Installing CA certificates to the SDX/SVM for LDAPS user authentication at Citrix Discussions for details.
    5. Enter the Base DN in LDAP format.
    6. Enter the bind account in UPN format, or Domain\Username format, or DN format.
    7. Check the box for Enable Change Password.
    8. Click Retrieve Attributes, and scroll down.
    9. For Server Logon Attribute, select sAMAccountName.
    10. For Group Attribute, select memberOf.
    11. For Sub Attribute Name, select CN.
    12. To prevent unauthorized users from logging in, configure a Search Filter as detailed in the LDAP post. Scroll down.
  4. Click Create.
  5. Expand System, expand User Administration, and click Groups.
  6. On the right, click Add.
  7. In the Create System Group page:
    1. Enter the case sensitive name of the Active Directory group.
    2. Check the box next to System Access.
    3. Configure the Session Timeout.
  8. Click Create.
  9. On the left, under System, click User Administration.
  10. On the right, click User Lockout Configuration.

    1. If desired, check the box next to Enable User Lockout, and configure the maximum logon attempts. Click OK.
  11. On the left, under System, click Authentication.
  12. On the right, click Authentication Configuration.

    1. Change the Server Type drop-down to EXTERNAL, and click Insert.
    2. Select the LDAP server you created earlier, and click OK.
    3. Make sure Enable fallback is enabled, and click OK.

SSL Certificate and Encryption

Replace SDX Management Service Certificate

To replace the Management Service certificate:

  1. PEM format: The certificate must be in PEM format. The Management Service does not provide any mechanism for converting a PFX file to PEM. You can convert from PFX to PEM by using the Import PKCS#12 task in a Citrix ADC instance.
  2. On the left, click System.
  3. On the right, in the left column, in the Set Up Appliance section, click Install SSL Certificate.
  4. Select the certificate and key files in PEM format. If the key file is encrypted, enter the password. Then click OK.
  5. The Management Service will restart. Only the SVM restarts; the Citrix ADC instances do not restart.


Force HTTPS to the Management Service

  1. Connect to the SVM using HTTPS. You can’t make this upcoming change if you are connected using HTTP.
  2. On the Configuration tab, click System.
  3. On the right, click Change System Settings.
  4. Check the box next to Secure Access Only, and click OK. This forces you to use HTTPS to connect to the Management Service.

SSL Encrypt Management Service to Citrix ADC Communication

From http://support.citrix.com/article/CTX134973: Communication from the Management Service to the Citrix ADC VPX instances is HTTP by default. If you want to configure HTTPS access for the Citrix ADC VPX instances, then you have to secure the network traffic between the Management Service and Citrix ADC VPX instances. If you do not secure the network traffic from the Management Service configuration, then the Citrix ADC VPX Instance State appears as Out of Service and the Status shows Inventory from instance failed.

  1. Log on to the Management Service .
  2. On the Configuration tab, click System.
  3. On the right, click Change System Settings.
  4. Change the Communication with NetScaler Instance drop-down to https, as shown in the following screen shot:
  5. Run the following command on the Citrix ADC VPX instance, to change the Management Access (-gui) to SECUREONLY: 
    set ns ip ipaddress -gui SECUREONLY
  6. Or in the Citrix ADC instance management GUI, go to Network > IPs, edit the NSIP, and then check the box next to Secure access only.

SDX/XenServer LACP Channels

For an overview of Citrix ADC SDX networking, see Citrix CTX226732 Introduction to Citrix NetScaler SDX

To use LACP, configure Channels in the Management Service, which creates them in XenServer. Then when provisioning an instance, connect it to the Channel.

  1. In the Management Service, on the Configuration tab, expand System, and click Channels.
  2. On the right, click Add.
  3. In the Create Channel page:
    1. Select a Channel ID.
    2. For Type, select LACP or STATIC. The other two options are for switch independent load balancing.
    3. In the Interfaces section, move the Channel Member interfaces to the right by clicking the right arrow.
    4. In the Settings section, for LACP you can select Long or Short, depending on switch configuration. Long is the default.
  4. Click Create when done.
  5. Click Yes when asked to proceed.
  6. The channel will then be created on XenServer.

VPX Instances – Provision

Admin profile

Admin profiles specify the nsroot user credentials for the instances. Management Service uses these nsroot credentials later when communicating with the instances to retrieve configuration data.

The default admin profile for an instance specifies a user name of nsroot, and the password is also nsroot. To specify a different nsroot password, create a new admin profile.

  • You can create a single admin profile that is used by all instances. To delegate administration, don’t give out the nsroot password to the instance administrators. One option is to enable LDAP inside the instance before granting access to a different department.
  • When creating an instance, there’s an option to create a non-nsroot account, which has almost the same permissions as nsroot, but leaves out some SDX specific features (e.g interfaces). This is another option for delegating administration to a different team.
  • Or you can create different admin profiles for different instances, which allows you to inform the different departments the nsroot password for their VPX instances.

Important: Do not change the password directly on the Citrix ADC VPX instance. If you do so, the instance becomes unreachable from the Management Service. To change a password, first create a new admin profile, and then modify the Citrix ADC instance, selecting this profile from the Admin Profile list.

  1. On the Configuration tab, in the navigation pane, expand Citrix ADC (or NetScaler), and then click Admin Profiles.
  2. In the Admin Profiles pane, click Add.
  3. In the Create Admin Profile dialog box, set the following parameters:
    • Profile Name*—Name of the admin profile.
    • User Name—User name used to log on to the Citrix ADC instances. The user name of the default profile is nsroot and cannot be changed.
    • Password*—The password used to log on to the Citrix ADC instance. Maximum length: 31 characters.
    • Confirm Password*—The password used to log on to the Citrix ADC instance.
    • Use global settings for NetScaler communication – you can uncheck this box and change the protocol to https.
  4. Click Create. The admin profile you created appears in the Admin Profiles pane.

Upload a Citrix ADC VPX .xva file

You must upload a Citrix ADC VPX .xva file to the SDX appliance before provisioning the Citrix ADC VPX instances. XVA files are only used when creating a new instance. Once the instance is created, use normal firmware upgrade procedures.

  1. Go to the Citrix ADC VPX download page.
  2. Download the Citrix ADC VPX for XenServer.
  3. After downloading, extract the .gz file (use 7-zip). You can’t upload the .gz file to SVM. You must extract it first.
  4. On the Configuration tab, in the navigation pane, expand Citrix ADC (or NetScaler), and then click Software Images.
  5. On the right, switch to the XVA Files tab, and then click Upload.
  6. In the Upload NetScaler Instance XVA dialog box, click Browse, and select the XVA image file that you want to upload. Click Upload.
  7. The XVA image file appears in the XVA Files pane after it is uploaded.

Provision a Citrix ADC instance

  1. On the SDX Management Service, go to the Dashboard page.
  2. On the bottom right, the System Resource Utilization pane shows you the amount of physical resources that are available for allocation.
  3. Click Core Allocation to see the number of cores available for assignment.

    1. In 12.0 build 57 and newer, click Crypto Capacity to see SSL capacity.
  4. On the Configuration tab, in the navigation pane, expand Citrix ADC (or NetScaler), and then click Instances.
  5. In the NetScaler Instances pane, click Add.
  6. In the Provision NetScaler section, enter a name for the instance.
  7. Enter the NSIP, mask, and Gateway.
  8. Nexthop to Management Service – If the instance’s NSIP is on a different subnet than the SVM IP, and if the instance’s default gateway is on a different network than the NSIP, then enter a next hop router address on the instance’s NSIP network, so the instance can respond to the SDX Management Service.
  9. In the XVA File field, you can Browse > Local to select an XVA file on your local machine that hasn’t been uploaded to SDX yet. Or you can Browse > Appliance, and select an XVA file that has already been uploaded to SDX.
  10. Select an Admin Profile created earlier. Or you can click the Add button or plus icon to create a new Admin Profile.
  11. Enter a Description. Scroll down.
  12. In the License Allocation section, change the Feature License to Platinum.
  13. For Throughput, partition your licensed bandwidth. If you are licensed for 40 Gbps, make sure the total of all VPX instances does not exceed that number.
  14. For Allocation Mode, Burstable is also an option. Fixed bandwidth can’t be shared with other instances. Burstable can be shared. See Bandwidth Metering in NetScaler SDX at Citrix Docs.
  15. If SDX 12.0 build 57 or newer, in the Crypto Allocation field, allocate at least one multiple of Asymmetric Crypto Units. Clicking the up arrow should increment in the correct multiple. See Managing Crypto Capacity at Citrix Docs. You can find the minimum by dividing the total Asymmetric Crypto Units by the Crypto Virtual Interfaces. Enter in a multiple of this result.

    1. On newer Citrix ADC hardware (e.g SDX 8900), you can also specif the Symmetric Crypto Units. Again, enter a multiple of the minimum.
    2. Citrix ADC SDX older than build 57 will instead ask for SSL Chips. Some SSL/TLS features require at least one chip.
  16. In the Resource Allocation section, consider changing the Total Memory to 4096.
  17. For CPU, for production instances, select one of the Dedicated options. Dev/Test instances can use Shared CPU. Then scroll down.
  18. In the Instance Administration section, you can optionally add an instance administrator. Enter a new local account that will be created on the VPX. This instance admin is in addition to the nsroot user. Note, networking functionality is not available to this account. Scroll down.

  19. In the Network Settings section, if the VPX NSIP is on the same network as the SDX SVM, then leave 0/1 selected, and deselect 0/2.
  20. Click Add to connect the VPX to more interfaces.
  21. If you have Port Channels, select one of the LA interfaces.
  22. If you configure any VLAN settings here, then XenServer filters the VLANs available to the VPX instance. Changing the VLAN filtering settings later probably requires a reboot. Click Add. Note: VLAN tagging is configured inside the instance, and not here.
  23. In the Management VLAN Settings section, do not configure anything in this section unless you need to tag the NSIP VLAN.
  24. Click Done.
  25. After a couple minutes the instance will be created. Look in the bottom right of Chrome to see the status.
  26. Click Close when it’s done booting.
  27. If you go to the Dashboard page…
  28. If you click an instance name, you can see how the instance is connected to the physical NICs.
  29. Back in Configuration > Citrix ADC > Instances, in your Instances list, click the blue IP address link to launch the VPX management console. Or, simply point your browser to the NSIP and login.
  30. Do the following at a minimum (instructions are in the NetScaler System Configuration article):
    1. Create Policy Based Route for the NSIP – System > Settings > Network > PBRs
    2. Add SNIPs for each VLAN – System > Network > IPs
    3. Add VLANs and bind to SNIPs – System > Network > VLANs
    4. Create Static Routes for internal networks – System > Network > Routes
    5. Change default gateway – System > Network > Routes > 0.0.0.0
    6. Create another instance on a different SDX, and High Availability pair them together – System > High Availability

VPX Instances – Manage

You may login to the VPX instance and configure everything normally. SDX also offers the ability to manage IP addresses, and SSL certificates, from SDX, rather than from inside the VPX instance. The SDX Management Service does not have the ability to create certificates, so it’s probably best to do that from within the VPX instance.

View the console of a Citrix ADC instance

  1. Connect to the SDX Management Service using https.
    1. Viewing the virtual machine console might not work unless you install a valid certificate for the SDX Management Service.
  2. In the Management Service, go to Configuration > Citrix ADC > Instances.
  3. On the right, right-click an instance, and click Console.
  4. The instance console then appears.
  5. Another option is to use the Lights Out Module, and the xl console command, as detailed at Citrix Blog Post SDX Remote Console Access of VIs.

Start, stop, delete, or restart a Citrix ADC instance

  1. On the Configuration tab, in the navigation pane, expand Citrix ADC (or NetScaler), and click Instances.
  2. On the right, in the Instances pane, right-click the Citrix ADC instance on which you want to perform the operation, and then click Start or Shut Down or Delete or Reboot.
  3. In the Confirm message box, click Yes.

Create a Subnet IP Address on a Citrix ADC Instance

  1. On the Configuration tab, in the navigation pane, click Citrix ADC.
  2. On the right, in the Citrix ADC Configuration pane, click Create IP.
  3. In the Create Citrix ADC IP dialog box, specify values for the following parameters.
    • IP Address* – Specify the IP address assigned as the SNIP address.
    • Netmask* – Specify the subnet mask associated with the SNIP address.
    • Type* – Specify the type of IP address. Possible values: SNIP.
    • Save Configuration* – Specify whether the configuration should be saved on the Citrix ADC . Default value is false.
    • Instance IP Address* – Specify the IP address of the Citrix ADC instance on which this SNIP will be created.
  4. Click Create.

Create a VLAN on a Citrix ADC instance

  1. Go to Citrix ADC > Instances.
  2. On the right, right-click an instance, and click VLAN Bindings.
  3. Click Add.
  4. Enter a VLAN ID, and select an interface.
  5. Check the box for Tagged if needed.
  6. Notice there’s no way to bind a SNIP to the VLAN. You do that inside the instance. Click Create.

Save the configuration of a Citrix ADC instance

  1. On the Configuration tab, in the navigation pane, click Citrix ADC.
  2. On the right, in the Citrix ADC pane, click Save Configuration.
  3. In the Save Configuration dialog box, in Instance IP Address, select the IP addresses of the Citrix ADC instances whose configuration you want to save.
  4. Click OK.

Change NSIP of VPX Instance

The best way to change the NSIP is to edit the instance. Go to Configuration > Citrix ADC > Instances, right-click an instance, and click Edit.

Then change the IPv4 Address at the top of the page. Click Done. SVM will push the configuration change to the instance.

If you change NSIP inside of VPX instead of Editing the Instance in the Management Service, see article CTX139206 How to Change NSIP of VPX Instance in SDX to adjust the XenServer settings.

Enable Call Home

  1. On the Configuration tab, in the navigation pane, click the Citrix ADC node.
  2. On the right, click Call Home.
  3. Enter an email address to receive communications regarding Citrix ADC Call Home.
  4. Check the box next to Enable Call Home.
  5. Click Add.
  6. Select the instances to enable Call Home by moving them to the right, and click OK.
  7. You can view the status of Call Home by expanding Citrix ADC, and clicking Call Home.
  8. The right pane indicates if it’s enabled or not. You can also configure Call Home from here.

VPX Instance – Firmware Upgrade

Upload Citrix ADC Firmware Build Files

To upgrade a VPX instance from the Management Service, first upload the firmware build file.

  1. Download the Citrix ADC firmware using the normal method. It’s in the Build section.
  2. On the SDX, in the Configuration tab, on the left, expand Citrix ADC (or NetScaler), and click Software Images.
  3. On the right, in the Software Images tab, click Upload.
  4. Browse to the build…tgz file, and click Open.

Upgrade Multiple NetScaler VPX Instances

You can upgrade multiple instances at the same time:

  1. To prevent any loss of the configuration running on the instance that you want to upgrade, save the configuration on the instance before you upgrade the instance.
  2. On the Configuration tab, in the navigation pane, expand Citrix ADC (or NetScaler), and click Instances.
  3. Right-click an instance, and click Upgrade.
  4. In the Upgrade Citrix ADC Instance dialog box, in Build File, select the Citrix ADC upgrade build file of the version you want to upgrade to. Click OK.
  5. Click Close when done.

Management Service Monitoring

  1. To view syslog, in the navigation pane, expand System, click Auditing, and then click Syslog Message in the right pane.
  2. To view the task log, in the navigation pane, expand Diagnostics, and then click Task Log.
  3. To view Management Service events, on the Configuration tab, in the expand System and click Events.
  4. Citrix ADC > Entities lets you see the various Load Balancing entities configured on the instances. You might have to click Poll Now to get them to show up.
  5. To view instance alerts, go to Citrix ADC > Events > All Events.
  6. There is also event reporting.

Management Service Backups

The SDX appliance automatically keeps three backups of the Management Service configuration that are taken daily at 12:30 am.

Backups in NetScaler SDX contain the following:

  • Single bundle image
  • NetScaler XVA image
  • NetScaler upgrade image
  • Management Service image
  • Management Service configuration
  • NetScaler SDX configuration
  • NetScaler configuration

You can go to Management Service > Backup Files to backup or restore the SDX appliance’s configuration. And you can download the backup files.

You can configure the number of retained backups by clicking System on the left, and then clicking Backup Policy in the right pane.

You can even transfer the backup files to an external system.

EUC Weekly Digest – September 2, 2017

Last Modified: Nov 7, 2020 @ 6:34 am

Leave a comment

Here are some EUC items I found interesting last week. For more immediate updates, follow me at http://twitter.com/cstalhood.

For a list of updates at carlstalhood.com, see the Detailed Change Log.

 

XenApp/XenDesktop

VDA

App Layering (Unidesk)

HDX

NetScaler

NetScaler MAS

NetScaler Gateway

XenMobile

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VMware Horizon Load Balancing – NetScaler / Citrix ADC

Last Modified: Jul 25, 2024 @ 12:06 pm

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Navigation

Use this procedure to load balance VMware Unified Access Gateway.

Change Log

Overview

To simplify this post, this post is focused on Unified Access Gateway, which is the replacement for Horizon Security Servers.

For load balancing of other Horizon components:

  • Internal Horizon Connection Servers – This is standard load balancing on SSL_BRIDGE protocol, port 443, and Source IP persistence. See the CLI commands for a sample configuration.
    • If you enabled the Secure Gateways (PCoIP, Blast) on the Connection Servers, then load balance the Connection Servers using the same procedure as load balancing UAGs.

UAG appliances vs Horizon Security Servers

There are two VMware-provided remote access solutions for Horizon View:

Unified Access Gateway appliances are preferred over Horizon Security Servers for the following reasons:

  • No need to pair with internal Connection Servers, which simplifies the configuration.
  • Linux appliance instead of Windows server.
  • Authentication can be offloaded to the Unified Access Gateway. This includes: Smart Cards, RSA, and RADIUS.
  • Blast Extreme Adaptive Transport (BEAT) in Horizon 7.1 and newer only works with Unified Access Gateway 2.9 and newer. Security Server and older Access Points don’t work.
    • VMware Blog Post Deep Dive into VMware Horizon Blast Extreme Adaptive Transport – Blast Extreme Adaptive Transport is enabled by default in VMware Horizon View 7.1 and Horizon Client 4.4. If the clients are connecting from outside the demilitarized zone (DMZ), you would also need to have VMware Unified Access Gateway (not Security Server) to take full advantage of the new transport. The adaptive transport will automatically sense the network for UDP availability and will fallback to legacy Blast TCP if UDP is not available.

Here is a typical Unified Access Gateway architecture:

  • Two Internal Connection Servers – these need to be load balanced on an internal VIP on TCP 443. Internal users connect to the internal VIP.
    • Instructions for load balancing the internal Connection Servers are not detailed in this post. Instead, see the CLI Commands.
  • Two DMZ Unified Access Gateway (Access Point) appliances – these need to be load balanced on a DMZ VIP on several ports. External users connect to the DMZ VIP.
    • Unified Access Gateway appliances connect to the internal Load Balancing VIP for the internal Connection Servers using HTTPS protocol
    • Unified Access Gateway appliances connect directly to Horizon Agents using Blast or PCoIP protocol.

During UAG configuration, you specify the address of the internal Connection Servers. The address you enter should be a DNS name that resolves to an internal load balancing VIP for the Connection Servers.

If you have split DNS, you can use the same DNS name for both external UAG access, and for internal Connection Server load balancing. Externally, configure the DNS name to resolve to the UAG Load Balancing VIP. Internally, configure the DNS name to resolve to the internal VIP that load balances the Connection Servers.

For Cloud Pod Architecture, configure separate VIPs in each datacenter. Then configure NetScaler Citrix ADC GSLB to resolve a single DNS name to multiple VIPs.

Protocols/Ports

To support Blast Extreme, PCoIP, and HTML Blast connectivity, the following ports must be load balanced to the UAGs:

  • TCP 443
  • UDP 443
  • TCP 4172
  • UDP 4172
  • TCP 8443
  • UDP 8443

The initial connection to UAG is always TCP 443 (HTTPS). If a user is load balanced on port 443 to a particular UAG, then the connection on UDP 4172 must go the same UAG. Normally load balancing persistence only applies to a single port number, so whatever UAG was selected for port 443, won’t be considered for the 4172 connection. But in NetScaler Citrix ADC, you can configure a Persistency Group to use a single persistency across multiple load balancing Virtual Servers with different port numbers. In F5, you configure Match Across Services, as detailed by Aresh Sarkari at Persistence Profile – F5 LTM Load Balancing for VMware Unified Access Gateway Appliance.

This topic primarily focuses on NetScaler Citrix ADC GUI configuration. Alternatively, you can skip directly to the CLI commands.

Load Balancing Monitors

Users connect to Unified Access Gateway appliances on multiple ports: TCP 443, UDP 443, TCP 8443, UDP 8443, TCP 4172, and UDP 4172. Create Load Balancing Monitors for each port number. Since UDP can’t be easily monitored, use TCP monitors as substitutes for UDP. That means you only need four monitors:

  • TCP 443 – HTTPS
    • HEAD /favicon.ico or GET /favicon.ico. This string can detect if UAG is in Quiesce mode, or if Connection Server is disabled in Horizon Console. See VMware 56636 for supported monitoring strings.
  • TCP 4172
  • TCP 8443

The procedure for configuring monitors changed in NetScaler 12.0 build 56 and newer.

SSL (443) Monitor for Connection Server Health

  1. On the left, expand Traffic Management, expand Load Balancing, and click Monitors.
  2. On the right, click Add.
  3. Name it Horizon-SSL or similar.
  4. In the Type field, click where it says Click to select.
  5. In the Monitor Types list, click the circle next to HTTP.
  6. Scroll up and click the blue Select button.
  7. To reduce UAG CPU, VMware recommends setting the Interval to 30 seconds.
  8. In the HTTP Request field, enter GET /favicon.ico. See VMware 56636 for supported health monitoring requests.
  9. Check the box next to Secure.
  10. Scroll down and click Advanced Parameters to expand it.
  11. In the Advanced Parameters section, in the Destination Port field, enter 443.
  12. Scroll down to the TROFS Code field and enter 503. When UAG is in Quiesce mode, TROFS will cause the service to transition to out of service allowing existing connections instead of directly going down and killing existing sessions. (h/t Henry Heres)
  13. Scroll down, and click Create.

PCoIP (4172) Monitor

  1. On the left, expand Traffic Management, expand Load Balancing, and click Monitors.
  2. On the right, click Add.
  3. Name it Horizon-PCoIP or similar.
  4. For the Type field, click where it says Click to select and select TCP from the Monitor Types list.
  5. Scroll down to Advanced Parameters, click Advanced Parameters to expand it, and then enter 4172 in the Destination Port field. This forces the monitor to connect to port 4172 even if the monitor is bound to a service group that is configured for a different port number.
  6. Scroll down, and click Create.

Blast (8443) Monitor

  1. On the left, expand Traffic Management, expand Load Balancing, and click Monitors.
  2. On the right, click Add.
  3. Name it Horizon-Blast or similar.
  4. For the Type field, click where it says Click to select and select TCP from the Monitor Types list.
  5. Scroll down to Advanced Parameters, click Advanced Parameters to expand it, and then enter 8443 in the Destination Port field. This forces the monitor to connect to port 8443 even if the monitor is bound to a service group that is configured for a different port number.
  6. Scroll down, and click Create.

UAG DDoS

NetScaler Citrix ADC Monitors might trigger UAG’s DDoS protection. To stop this: (source = UAG breaks after a few days. They break 100% of the time. at VMware Discussions)

  1. Point your browser to the UAG appliance’s admin interface using https, port 9443 and path /admin.
  2. Login to the admin interface.
  3. On the right, under Configure Manually, click Select.
  4. In the Advanced Settings section, click the gear icon for System Configuration.
  5. Scroll down.
  6. Change Request Timeout to 0.
  7. Change Body Receive Timeout to 0.
  8. Click Save.

Load Balancing Servers

Create Load Balancing Server Objects for the DMZ Unified Access Gateway appliances.

  1. On the left, expand Traffic Management, expand Load Balancing, and click Servers.
  2. On the right, click Add.
  3. Enter a descriptive server name, usually it matches the actual appliance name.
  4. Enter the IP address of a Unified Access Gateway appliance.
  5. Enter comments to describe the server. Click Create.
  6. Continue adding Unified Access Gateway appliances.

Load Balancing Service Groups

Overview

Since there are six protocol/ports to UAG, there will be six service groups – one for each protocol/port:

  • TCP 443 – SSL_BRIDGE
  • UDP 443
  • UDP 4172
  • TCP 4172
  • TCP 8443 – SSL_BRIDGE
  • UDP 8443

Users will initially connect to TCP port 443, and then must be redirected to one of the other ports on the same UAG appliance that was initially used for the TCP 443 connection. If TCP 443 is up, but UDP 4172 is down on the same appliance, then you probably TCP 443 to go down too. To facilitate this, bind all three port number monitors to the TCP 443 service. If any of the bound monitors goes down, then TCP 443 is also taken down.

  • Only the TCP 443 service group needs to monitor all port numbers.
  • Other port number service groups only need to monitor that specific port number. For example, the TCP 8443 Service Group should monitor port TCP 8443.
  • Since UDP is difficult to monitor, the UDP Service Groups will monitor the equivalent TCP port. For example, the UDP 4172 Service Group will monitor TCP 4172. This isn’t the best option, but it’s better than ping.

TCP 443 Load Balancing Service Group

  1. On the left, expand Traffic Management, expand Load Balancing, and click Service Groups.
  2. On the right, click Add.
  3. Give the Service Group a descriptive name (e.g. svcgrp-Horizon-SSL).
  4. Change the Protocol to SSL_BRIDGE.
  5. Click OK to close the Basic Settings section.
  6. On the left, in the Service Group Members section, click where it says No Service Group Member.

    1. Change the selection to Server Based.
    2. In the Select Server field, click where it says Click to select.
    3. Select the Unified Access Gateway appliances you created earlier, and then at the top of the page click the blue Select button.
    4. In the Port field, enter 443, and click Create.
  7. Click OK to close the Service Group Members section.
  8. On the right, in the Advanced Settings column, click Monitors to move it to the left.
  9. On the left, at the bottom of the page, in the Monitors section, click where it says No Service Group to Monitor Binding.

    1. In the Select Monitor field, click where it says Click to select.
    2. Click the circle next to the Horizon-SSL monitor, and then at the top of the page click the blue Select button.
    3. Click Bind.
  10. For load balancing UAGs, this Service Group should monitor all port numbers so that if any of the port numbers are down then the entire server should no longer receive connections. If load balancing internal Connection Servers, then you don’t need to bind any more monitors since the PCoIP Gateway and Blast Gateway are usually disabled. To bind more monitors, on the left, click where it says 1 Service Group to Monitor Binding.

    1. Click Add Binding.
    2. In the Select Monitor field, click where it says Click to select.
    3. Click the circle next to the Horizon-PCoIP monitor, and then at the top of the page click the blue Select button.
    4. Then click Bind.
    5. Repeat these steps to bind the Horizon-Blast monitor. Unfortunately you can only bind one monitor at a time.
      • If any of these monitors goes down, then the UAG is taken offline.
    6. Click Close.
  11. To verify the monitors, on the left, higher up the page in the Service Group Members section, click the line that says # Service Group Members.

    1. Right-click one of the members, and click Monitor Details.
    2. The Last Response should indicate Success. If you bound multiple monitors to the Service, then the member will only be UP if all monitors succeed.

      • UAG has a Quiesce mode, which tells the load balancer to stop sending it connections. You can enable Quiesce mode in the UAG’s System Configuration menu.
      • Connection Servers can be disabled.
      • If Quiesce mode is enabled on the UAG, or if the Connection Server is disabled, then the member of the service group will show Going Out of Service. You can see this by right-clicking on the Server Group and clicking Manage Members.

    3. Click Close when done.
  12. Then click Done to finish creating the Service Group.

Other Ports Load Balancing Service Groups

Here are general instructions for the other Horizon UAG load balancing service groups.

  1. On the left, go to Traffic Management > Load Balancing > Service Groups.
  2. On the right, click Add.
  3. Name it svcgrp-Horizon-UDP443 or similar.
  4. Change the Protocol to UDP. Click OK to close the Basic Settings section.
  5. On the left, click where it says No Service Group Member.

    1. Change the selection to Server Based, and then click Click to select.
    2. Select your multiple Unified Access Gateway appliances, and then at the top of the page click the blue Select button.
    3. Enter 443 as the Port. Click Create.
  6. Click OK to close the Service Group Members section.
  7. On the right, in the Advanced Settings column, click Monitors to move it to the left.

    1. On the left, in the Monitors section, click where it says No Service Group to Monitor Binding.
    2. For the Select Monitor field, click where it says Click to select.
    3. Select the Horizon-SSL monitor, click Select, and then click Bind. Since we don’t have a UDP monitor, we’re binding the TCP monitor instead.
  8. Click Done to finish creating the Service Group for UDP 443.
  9. Add another Service Group for PCoIP on TCP 4172.
    1. Name = svcgrp-Horizon-PCoIPTCP or similar.
    2. Protocol = TCP
    3. Members = multiple Unified Access Gateway appliances.
    4. Port = 4172.
    5. Monitors = Horizon-PCoIP. You can add the other monitors if desired.
  10. Add another Service Group for PCoIP on UDP 4172.
    1. Name = svcgrp-Horizon-PCoIPUDP or similar.
    2. Protocol = UDP
    3. Members = multiple Unified Access Gateway appliances
    4. Port = 4172.
    5. Monitors = Horizon-PCoIP. You can add the other monitors if desired.
  11. Add another Service Group for SSL_BRIDGE 8443.
    1. Name = svcgrp-Horizon-TCP8443 or similar.
    2. Protocol = SSL_BRIDGE
    3. Members = multiple Unified Access Gateway appliances
    4. Port = 8443.
    5. Monitors = Horizon-Blast. You can add the other monitors if desired.
  12. Add another Service Group for UDP 8443 (Blast Extreme in Horizon 7).
    1. Name = svcgrp-Horizon-UDP8443 or similar.
    2. Protocol = UDP
    3. Members = multiple Unified Access Gateway appliances
    4. Port = 8443.
    5. Monitors = Horizon-Blast. You can add the other monitors if desired.
  13. The six service groups should look something like this:

Load Balancing Virtual Servers

Unified Access Gateway appliances listen on multiple ports so you will need separate load balancers for each port number. Here is a summary of their Virtual Servers, all listening on the same Virtual IP address:

  • Virtual Server on SSL_BRIDGE 443 – bind the SSL_BRIDGE 443 service group.
  • Virtual Server on UDP 443 (Horizon 7) – bind the UDP 443 service group.
  • Virtual Server on UDP 4172 – bind the PCoIP UDP service group.
  • Virtual Server on TCP 4172 – bind the PCoIP TCP service group.
  • Virtual Server on SSL_BRIDGE 8443 – bind the SSL_BRIDGE 8443 service group.
  • Virtual Server on UDP 8443 (Horizon 7) – bind the UDP 8443 service group.

Do the following to create the Virtual Servers:

  1. On the left, under Traffic Management > Load Balancing, click Virtual Servers.
  2. On the right, click Add.
  3. In the Basic Settings section:
    1. Name it lbvip-Horizon-SSL or similar.
    2. Change the Protocol to SSL_BRIDGE.
    3. Specify a new VIP. This one VIP will be used for all of the Virtual Servers.
    4. Enter 443 as the Port.
  4. Click OK to close the Basic Settings section.
  5. On the left, in the Services and Service Groups section, click where it says No Load Balancing Virtual Server ServiceGroup Binding.

    1. Click where it says Click to select.
    2. Click the circle next to the Horizon-SSL Service Group, and then at the top of the page click the blue Select button.
    3. Click Bind.
  6. Click Continue to close the Services and Service Groups section.
  7. Then click Done to finish creating the Load Balancing Virtual Server. Persistence will be configured later.
  8. Create another Load Balancing Virtual Server for UDP 443. You can right-click the existing Load Balancing Virtual Server and click Add to copy some settings.

    1. Name = lbvip-Horizon-UDP443
    2. Same VIP as the TCP 443 Load Balancer.
    3. Protocol = UDP, Port = 443
    4. Service Group Binding = the UDP 443 Service Group

  9. Create another Load Balancing Virtual Server for PCoIP UDP 4172:
    1. Name = lbvip-Horizon-PCoIPUDP
    2. Same VIP as the 443 Load Balancer.
    3. Protocol = UDP, Port = 4172
    4. Service Group Binding = the PCoIP UDP Service Group.

  10. Create another Load Balancing Virtual Server for PCoIP TCP 4172:
    1. Name = lbvip-Horizon-PCoIPTCP
    2. Same VIP as the 443 Load Balancer.
    3. Protocol = TCP, Port = 4172
    4. Service Group Binding = the PCoIP TCP Service Group

  11. Create another Load Balancing Virtual Server for SSL_BRIDGE 8443:
    1. Name = lbvip-Horizon-8443SSL
    2. Same VIP as the 443 Load Balancer.
    3. Protocol = SSL_BRIDGE, Port = 8443
    4. Service Group Binding = the TCP 8443 SSL_BRIDGE Service Group

  12. Create another Load Balancing Virtual Server for UDP 8443:
    1. Name = lbvip-Horizon-8443UDP
    2. Same VIP as the 443 Load Balancer.
    3. Protocol = UDP, Port = 8443
    4. Service Group Binding = the UDP 8443 Service Group

  13. This gives you six Load Balancing Virtual Servers on the same VIP, but different protocols and port numbers.

Persistency Group

Users will first connect to SSL_BRIDGE 443 and be load balanced. Subsequent connections to the other port numbers must go to the same load balanced appliance. Create a Persistency Group to facilitate this.

  1. On the left, under Traffic Management, expand Load Balancing, and click Persistency Groups.
  2. On the right, click Add.
  3. Give the Persistency Group a name (e.g. Horizon).
  4. Change the Persistence drop-down to SOURCEIP.
  5. Enter a Time-out that is equal to, or greater than the timeout in Horizon View Administrator, which defaults to 10 hours (600 minutes).
  6. In the Virtual Server Name section, click Add.
  7. Move all six Horizon Load Balancing Virtual Servers to the right. Click Create.

Horizon Connection Server Locked.properties File

Horizon Connection Server’s default security settings might prevent you from connecting to load balanced Connection Servers and/or Unified Access Gateways. On the Connection Servers, go to C:\Program Files\VMware\VMware View\Server\sslgateway\conf, edit or create locked.properties file, and enter the following:

allowUnexpectedHost=true
checkOrigin=false
enableCORS=false

More details at VMware 2144768 Accessing the Horizon View Administrator page displays a blank error window in Horizon and 85801 Cross-Origin Resource Sharing (CORS) with Horizon 8 and loadbalanced HTML5 access. allowUnexpectedHost defaults to false in Horizon 2306 and Horizon 2212.1 and newer. Another option is to add portalHost entries as detailed at Allow HTML Access Through a Gateway at VMware Docs.

Load Balancing CLI Commands

Internal Connection Server Load Balancing

add server VCS01 10.2.2.19
add server VCS02 10.2.2.20
add serviceGroup svcgrp-VCS-SSL SSL_BRIDGE
add lb vserver lbvip-Horizon-SSL SSL_BRIDGE 10.2.5.203 443 -persistenceType SOURCEIP -timeout 600
bind lb vserver lbvip-Horizon-SSL svcgrp-VCS-SSL
add lb monitor Horizon-SSL HTTP -respCode 200 -httpRequest "GET /favicon.ico" -destPort 443 -secure YES
bind serviceGroup svcgrp-VCS-SSL VCS01 443
bind serviceGroup svcgrp-VCS-SSL VCS02 443
bind serviceGroup svcgrp-VCS-SSL -monitorName Horizon-SSL

Unified Access Gateway load balancing with Blast and PCoIP

add server UAG01 10.2.2.187
add server UAG02 10.2.2.188
add serviceGroup svcgrp-Horizon-SSL SSL_BRIDGE
add serviceGroup svcgrp-Horizon-UDP443 UDP
add serviceGroup svcgrp-Horizon-PCoIPTCP TCP
add serviceGroup svcgrp-Horizon-PCoIPUDP UDP
add serviceGroup svcgrp-Horizon-TCP8443 SSL_BRIDGE
add serviceGroup svcgrp-Horizon-UDP8443 UDP
add lb vserver lbvip-Horizon-SSL SSL_BRIDGE 10.2.5.204 443
add lb vserver lbvip-Horizon-UDP443 UDP 10.2.5.204 443
add lb vserver lbvip-Horizon-PCoIPUDP UDP 10.2.5.204 4172
add lb vserver lbvip-Horizon-PCoIPTCP TCP 10.2.5.204 4172
add lb vserver lbvip-Horizon-8443SSL SSL_BRIDGE 10.2.5.204 8443
add lb vserver lbvip-Horizon-8443UDP UDP 10.2.5.204 8443
bind lb vserver lbvip-Horizon-SSL svcgrp-Horizon-SSL
bind lb vserver lbvip-Horizon-UDP443 svcgrp-Horizon-UDP443
bind lb vserver lbvip-Horizon-PCoIPTCP svcgrp-Horizon-PCoIPTCP
bind lb vserver lbvip-Horizon-PCoIPUDP svcgrp-Horizon-PCoIPUDP
bind lb vserver lbvip-Horizon-8443SSL svcgrp-Horizon-TCP8443
bind lb vserver lbvip-Horizon-8443UDP svcgrp-Horizon-UDP8443
add lb group Horizon -persistenceType SOURCEIP -timeout 600
bind lb group Horizon lbvip-Horizon-SSL
bind lb group Horizon lbvip-Horizon-UDP443
bind lb group Horizon lbvip-Horizon-PCoIPUDP
bind lb group Horizon lbvip-Horizon-PCoIPTCP
bind lb group Horizon lbvip-Horizon-8443SSL
bind lb group Horizon lbvip-Horizon-8443UDP
set lb group Horizon -persistenceType SOURCEIP -timeout 600
add lb monitor Horizon-SSL HTTP -respCode 200 -httpRequest "GET /favicon.ico" -destPort 443 -secure YES -trofscode 503
add lb monitor Horizon-PCoIP TCP -LRTM DISABLED -destPort 4172 -secure YES
add lb monitor Horizon-Blast TCP -LRTM DISABLED -destPort 8443 -secure YES
bind serviceGroup svcgrp-Horizon-SSL UAG01 443
bind serviceGroup svcgrp-Horizon-SSL UAG02 443
bind serviceGroup svcgrp-Horizon-SSL -monitorName Horizon-SSL
bind serviceGroup svcgrp-Horizon-SSL -monitorName Horizon-PCoIP
bind serviceGroup svcgrp-Horizon-SSL -monitorName Horizon-Blast
bind serviceGroup svcgrp-Horizon-UDP443 UAG01 443
bind serviceGroup svcgrp-Horizon-UDP443 UAG02 443
bind serviceGroup svcgrp-Horizon-UDP443 -monitorName Horizon-SSL
bind serviceGroup svcgrp-Horizon-PCoIPTCP UAG01 4172
bind serviceGroup svcgrp-Horizon-PCoIPTCP UAG02 4172
bind serviceGroup svcgrp-Horizon-PCoIPTCP -monitorName Horizon-PCoIP
bind serviceGroup svcgrp-Horizon-PCoIPUDP UAG01 4172
bind serviceGroup svcgrp-Horizon-PCoIPUDP UAG02 4172
bind serviceGroup svcgrp-Horizon-PCoIPUDP -monitorName Horizon-PCoIP
bind serviceGroup svcgrp-Horizon-TCP8443 UAG01 8443
bind serviceGroup svcgrp-Horizon-TCP8443 UAG02 8443
bind serviceGroup svcgrp-Horizon-TCP8443 -monitorName Horizon-Blast
bind serviceGroup svcgrp-Horizon-UDP8443 UAG01 8443
bind serviceGroup svcgrp-Horizon-UDP8443 UAG02 8443
bind serviceGroup svcgrp-Horizon-UDP8443 -monitorName Horizon-Blast

Citrix Director Load Balancing – Citrix ADC

Last Modified: Mar 9, 2022 @ 4:21 pm

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Navigation

Change Log

  • 2018 Dec 20 – updated screenshots for ADC 12.1 build 50.
  • 2017 Dec 25 – updated entire article for 12.0 build 56. Monitor section has new 12.0 build 56 instructions.

Monitor

12.0 build 56 and newer

Instructions for creating the monitor changed in 12.0 build 56 and newer. If your build is older, skip to the older instructions.

  1. On the left, expand Traffic Management, expand Load Balancing, and click Monitors.
  2. On the right, click Add.
  3. Name it Director or similar.
  4. In the Type field, click where it says Click to select.
  5. Scroll down and click the circle next to HTTP.
  6. At the top of the window, click the blue Select button.
  7. Scroll down the Basic  Parameters section, and check the box next to Secure. This checkbox instructs the monitor to connect to the Director Servers using https/SSL/TLS instead of http.
  8. In the HTTP Request box, enter GET /Director/LogOn.aspx?cc=true.
  9. If Single Sign-on (Windows Integrated Authentication) is enabled on Director, then you might have to add 302 as a Response Code.
  10. Scroll down, and click Create.
  11. Jump to the Servers section.

12.0 older than build 56

  1. On the left, expand Traffic Management, expand Load Balancing, and click Monitors.
  2. On the right, click Add.
  3. Name it Director or similar.
  4. Change the Type drop-down to HTTP.
  5. If you will use SSL to communicate with the Director servers, then on the Standard Parameters tab, scroll down, and check the box next to Secure.
  6. Scroll up, and switch to the Special Parameters tab.
  7. In the HTTP Request field, enter GET /Director/LogOn.aspx?cc=true
    1. If Single Sign-on is enabled on Director, then you might have to add 302 as a Response Code.
  8. Scroll down, and click Create.

Servers

  1. On the left, expand Traffic Management, expand Load Balancing, and click Servers.
  2. On the right, click Add.
  3. Enter a descriptive server name. Usually it matches the actual server name.
  4. Enter the IP address of the Director server.
  5. Enter comments to describe the server. Click Create.
  6. Continue adding Director servers.

Service Group

  1. On the left, expand Traffic Management, expand Load Balancing, and click Service Groups.
  2. On the right, click Add.
  3. Give the Service Group a descriptive name (e.g. svcgrp-Director-SSL).
  4. Change the Protocol to HTTP or SSL, depending on if IIS on the Director server is enabled for https or not.
    • If the protocol is SSL, ensure the Monitor for Director has Secure enabled, as detailed earlier.
  5. Scroll down, and click OK.

  6. On the left, in the Service Group Members section, click where it says No Service Group Member.

    1. Change the selection to Server Based, and then Click to select the Director server objects.

    2. Enter 80 or 443 as the port. Then click Create.
  7. Click OK to close the Service Group Members section.
  8. On the right, under Advanced Settings, click Monitors.
  9. On the left, in the Monitors section, click where it says No Service Group to Monitor Binding.

    1. Click where it says to Click to select.
    2. Click the circle next to the Director monitor you created earlier. The monitor might be on Page 2.
      • The circle must be clicked exactly (no room for error). If you click outside the circle, then the monitor will open for editing. If this happens, click Close to return to the selection screen.
    3. At the top of the window, click the blue Select button.
    4. Then click Bind.
  10. To verify that the monitor is working, on the left, in the Service Group Members section, click the Service Group Members line.
  11. Right-click a member, and click Monitor Details.
  12. The Last Response should be Success – HTTP response code 200 received. Click Close twice.
  13. Then click Done.

Responder

Create a Responder policy to redirect users from the root page to /Director.

  1. Go to AppExpert > Responder, and enable the feature if it isn’t already enabled.
  2. Go to AppExpert > Responder > Actions.
  3. On the right, click Add.

    1. Give the Action a name (e.g. Director_Redirect).
    2. Change the Type to Redirect.
    3. In the Expression box, enter "/Director", including the quotes.
  4. On the bottom, click Create.
  5. Go to AppExpert > Responder > Policies.
  6. On the right, click Add.

    1. Give the Policy a name (e.g. Director_Redirect).
    2. Select the previously created Action.
    3. In the Expression box, enter HTTP.REQ.URL.PATH.EQ("/")
  7. On the bottom, click Create.

Load Balancing Virtual Server

  1. Create or install a certificate that will be used by the SSL Virtual Server. This certificate must match the DNS name for the load balanced Director servers.
  2. On the left, under Traffic Management > Load Balancing, click Virtual Servers.
  3. On the right, click Add.
  4. Do the following in the Basic Settings section:
    1. Name it lbvip-Director-SSL or similar.
    2. Change the Protocol to SSL.
    3. Specify a new internal VIP.
    4. Enter 443 as the Port.
    5. Click OK to close the Basic Settings section.
  5. On the left, in the Services and Service section, click where it says No Load Balancing Virtual Server ServiceGroup Binding.

    1. Click where it says Click to select.
    2. Click the circle next to a previously created Service Group. It might be on page 2.
      • The circle must be clicked exactly (no room for error). If you click outside the circle, then the Service Group will open for editing. If this happens, click the x on the top right, or the Done button on the bottom, to return to the selection screen.
    3. At top of the screen, click the blue Select button.
    4. Click Bind.
  6. Click Continue to close the Services and Service Groups section.
  7. Click where it says No Server Certificate.

    1. Click where it says Click to select.
    2. Click the circle next to a certificate that matches the FQDN that resolves to this VIP. It might be on page 2.
    3. At the top of the window, click the blue Select button.
    4. Click Bind.
  8. Click Continue to close the Certificate section.
  9. On the right, in the Advanced Settings column, click Persistence.
  10. On the left, in the Persistence section, do the following:
    1. Change the Persistence drop-down to COOKIEINSERT. The Persistence section in 12.0 build 56 and newer is slightly different than older builds.
    2. Set the Time-out to 0 minutes. This makes it a session cookie instead of a persistent cookie.
    3. Set the Backup Persistence to SOURCEIP.
    4. Set the Backup Time-out to match the timeout of Director. The default timeout for Director is 245 minutes.
    5. The IPv4 Netmask should default to 32 bits.
    6. Click OK to close the Persistence section.
  11. On the right, in the Advanced Settings section, add the Policies section.
  12. On the left, in the Policies section, click the plus icon.

    1. Change the Choose Policy drop-down to Responder, and click Continue.
    2. Click to select the previously created Director_Redirect policy.

      • The circle next to the Responder policy must be clicked exactly (no room for error). If you click outside the circle, then the policy will open for editing. If this happens, click Close to return to the selection screen.
    3. After selecting, click Bind.
  13. If you haven’t enabled the Default SSL Profile, then perform other normal SSL configuration including: disable SSLv3, bind a Modern A+ Cipher Group, and enable Strict Transport Security.

SSL Redirect

Do one of the following to configure a redirect from HTTP to HTTPS:

SSL Warning

  1. If you are doing SSL Offload (SSL on front end, HTTP on back end), when connecting to Director, it might complain about “You are not using a secure connection”.
  2. To turn off this warning, login to the Director servers, and run IIS Manager.
  3. On the left, navigate to Server > Sites > Default Web Site > Director.
  4. In the middle, double-click Application Settings.
  5. Change UI.EnableSslCheck to false.

CLI Commands

Here is a list of NetScaler CLI commands for Director Load Balancing:

# SSL Global Parameters
set ssl parameter -denySSLReneg NONSECURE

# Certs
add ssl certKey WildcardCorpLocal -cert WildcardCorpLocal.pfx -key WildcardCorpLocal.pfx -inform PFX -passcrypt "Passw0rd"

# SSL Cipher Group
add ssl cipher custom-ssllabs-cipher
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1.2-ECDHE-RSA-AES256-GCM-SHA384 -cipherPriority 1
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1.2-ECDHE-RSA-AES128-GCM-SHA256 -cipherPriority 2
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1.2-ECDHE-RSA-AES-256-SHA384 -cipherPriority 3
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1.2-ECDHE-RSA-AES-128-SHA256 -cipherPriority 4
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1-ECDHE-RSA-AES256-SHA -cipherPriority 5
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1-ECDHE-RSA-AES128-SHA -cipherPriority 6
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1.2-DHE-RSA-AES256-GCM-SHA384 -cipherPriority 7
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1.2-DHE-RSA-AES128-GCM-SHA256 -cipherPriority 8
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1-DHE-RSA-AES-256-CBC-SHA -cipherPriority 9
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1-DHE-RSA-AES-128-CBC-SHA -cipherPriority 10
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1-AES-256-CBC-SHA -cipherPriority 11
bind ssl cipher custom-ssllabs-cipher -cipherName TLS1-AES-128-CBC-SHA -cipherPriority 12

# Responder Actions
add responder action Director_Redirect redirect "\"/Director\"" -responseStatusCode 302

# Responder Policies
add responder policy Director_Redirect "HTTP.REQ.URL.PATH.EQ(\"/\")" Director_Redirect

# Load Balancing Global Parameters
enable ns mode FR L3 Edge USNIP PMTUD ULFD
set ns param -cookieversion 1
set ns tcpParam -WS ENABLED -SACK ENABLED
set ns httpParam -dropInvalReqs ON

# Monitors
add lb monitor Director HTTP -respCode 200 302 -httpRequest "GET /Director/LogOn.aspx?cc=true" -LRTM DISABLED -secure YES

# Servers
add server Director01 xdc01.corp.local
add server Director02 xdc02.corp.local

# Service Groups
add serviceGroup svcgrp-Director-SSL SSL -maxClient 0 -maxReq 0 -cip DISABLED -usip NO -useproxyport YES -cltTimeout 180 -svrTimeout 360 -CKA NO -TCPB NO -CMP YES
bind serviceGroup svcgrp-Director-SSL Director01 443
bind serviceGroup svcgrp-Director-SSL Director02 443
bind serviceGroup svcgrp-Director-SSL -monitorName Director

# Load Balancing Virtual Servers
add lb vserver lbvip-Director-SSL SSL 10.2.5.210 443 -persistenceType COOKIEINSERT -timeout 0 -persistenceBackup SOURCEIP -backupPersistenceTimeout 245 -cltTimeout 180 -redirectFromPort 80 -httpsRedirectUrl "https://director.corp.com"
bind lb vserver lbvip-Director-SSL svcgrp-Director-SSL
bind lb vserver lbvip-Director-SSL -policyName Director_Redirect -priority 100 -gotoPriorityExpression END -type REQUEST

# SSL Virtual Servers
set ssl vserver lbvip-Director-SSL -ssl3 DISABLED -HSTS ENABLED -maxage 157680000
unbind ssl vserver lbvip-Director-SSL -cipherName ALL
bind ssl vserver lbvip-Director-SSL -cipherName custom-ssllabs-cipher
bind ssl vserver lbvip-Director-SSL -certkeyName WildcardCorpLocal
bind ssl vserver lbvip-Director-SSL -eccCurveName P_256
bind ssl vserver lbvip-Director-SSL -eccCurveName P_384
bind ssl vserver lbvip-Director-SSL -eccCurveName P_224
bind ssl vserver lbvip-Director-SSL -eccCurveName P_521

SSL VPN – Citrix Gateway

Last Modified: May 5, 2021 @ 7:53 am

140 Comments

Navigation

💡 = Recently Updated

Change Log

Overview

Here’s an overview of the Citrix Gateway connection process:

  1. Users use SSL/TLS to connect to a Citrix Gateway Virtual Server (VIP).
  2. Citrix Gateway prompts the user for authentication.
  3. Once the user is authenticated, Citrix Gateway uses Session Policies/Profiles to determine what happens next.

Citrix Gateway supports six different connection methods:

  • ICA Proxy to Citrix Virtual Apps and Desktops (CVAD) (aka XenApp/XenDesktop) and StoreFront – the client is built into Citrix Workspace app (aka Citrix Receiver)
  • SSL VPN – requires installation of Citrix Gateway plug-in (VPN client)
  • Clientless – browser only, no VPN client, uses rewrite
  • Secure Browse – from MDX-wrapped mobile applications (Citrix Endpoint Management aka XenMobile), uses rewrite
  • RDP Proxy – only RDP client is needed
  • PCoIP Proxy – only VMware Horizon Client is needed

You can configure Citrix Gateway Session Policies/Profiles to only use one of the connection methods. Or Citrix Gateway can be configured to let users choose between ICA Proxy, Clientless, and SSL VPN connection methods. Here’s a sample Client Choices screen using the RfWebUI theme:

  • The Clientless Access option opens a portal page that has icons from Citrix StoreFront (ICA Proxy), icons for RDP Proxy, icons for PCoIP Proxy, and links to websites.
    • The website links can be proxied through Citrix Gateway. Proxy methods include: clientless rewrite, SSL VPN, and traditional load balancing.
    • Citrix Gateway can optionally Single Sign-on to the websites.
  •  The Virtual App and Desktop Access option only displays icons from Citrix StoreFront (ICA Proxy). For other types of icons, you’ll need Clientless Access.
  • The Connect with Citrix Gateway Plug-in option launches the VPN tunnel. After the tunnel is established, a portal page is displayed. This can be the Clientless Access portal, or a user defined website URL (e.g. intranet).

Session Policies/Profiles have several settings that control the behavior seen after authentication:

  • ICA Proxy – ON or OFF
    • If ON, then ICA Proxy is the only connection method allowed, overriding the other connection methods.
    • ICA Proxy does not launch the VPN client. It only needs Citrix Workspace app.
    • ICA Proxy shows the Webpage that’s configured in the Web Interface Address field of the Session Profile. This is typically the StoreFront Receiver for Web page, but technically it can be any internal website.
    • If OFF, that doesn’t mean ICA Proxy doesn’t work. You can still send ICA traffic to the Citrix Gateway Virtual Server, and the Citrix Gateway Virtual Server will still proxy it to internal VDAs.
    • Setting it to OFF allows the other connection methods to function. For example, Clientless Access can show both Citrix Gateway Bookmarks and StoreFront published apps. If VPN is launched, then the portal page shown to the user after the tunnel is established can contain the StoreFront published applications.
  • Clientless Access – On, Off, Disabled
    • If On, then Clientless is the only connection method allowed, assuming ICA Proxy is not set to ON. After the user logs in, the user is presented with a portal page that contains a list of Gateway bookmarks and/or StoreFront published icons. The VPN Client is not launched.
    • The Home Page setting in the Session Profile allows you to display an internal website instead of displaying the Citrix Gateway Portal Page.
    • Bookmarks are configured at Citrix Gateway > Resources > Bookmarks. You can bind the Bookmarks (Urls) to the Citrix Gateway Virtual Server, or to AAA Groups.
    • Only Bookmarks configured for Clientless Access will work without a VPN. The internal websites are rewritten so they are proxied through Citrix Gateway. For example, if the internal website is http://intranet.corp.local, then Gateway rewrites them to https://gateway.corp.com/cvpn/http/internal.corp.local. This causes the web browser to send the HTTP Request to Citrix Gateway, which then forwards the HTTP Request to the internal web server. No VPN needed.
  • Plug-in Type – Windows/MAC OS X
    • If both Clientless and ICA Proxy are set to Off, then the VPN Client will be downloaded and launched.
    • Once the VPN tunnel is established, the webpage configured in the Home Page setting is displayed. Or the Citrix Gateway Portal Page (Clientless Access) is displayed if no Home Page is configured. The Bookmarks in the Portal Page can link to internal websites that are only accessible through a VPN tunnel. Or Bookmarks can be configured for Clientless Access.
    • Additional Gateway objects control VPN behavior including: DNS Suffix, Intranet Applications, Intranet IPs, and Authorization Policies.
  • Client Choices – checked or unchecked
    • If Client Choices is checked, then it displays a page containing up to three buttons allowing the user to choose between VPN, Clientless, or StoreFront. The Network Access with the Citrix Gateway Plug-in (VPN) button is always displayed. The Clientless Access button is displayed if Clientless Access is set to On or Off (not Disabled). The Virtual App and Desktop Access button is displayed if a Web Interface Address is configured.

Here are some characteristics of Session Policies:

  • Citrix Gateway > Global Settings > Change Global Settings has the same settings as a Session Profile. However, all Session Policies/Profiles override the settings configured in Global Settings. That’s the whole point of the Override Global checkboxes in the Session Profiles.
  • Session Policy Expression – If the Session Policy Expression is true, then the settings contained in the Session Profile are applied.
    • Action = Session Profile – The Session Profile is also sometimes called the Action. That’s because all Citrix ADC policies follow a standard structure – if the expression evaluates to True, then perform the Action. For Session Policies in particular, the policy Action = Session Profile.
    • EPA – The Session Policy Expression in Classic Syntax could include an Endpoint Analysis (EPA) expression.
  • Default Syntax Expressions vs Classic Syntax Policy Expressions – Citrix ADC 12 and newer supports Default (Advanced) Syntax Expressions on Session Policies, in addition to the older Classic Syntax.
    • No syntax mixing – All Session Policies bound anywhere must be either Default or Classic. You cannot mix the two types.
    • EPA is Classic only – EPA Scans are only supported in Classic Expressions.
    • AD Group in Default Syntax – Default Syntax allows expressions for AD Group Membership like HTTP.REQ.USER.IS_MEMBER_OF("MyADGroup"). This could eliminate AAA Groups in some circumstances.
  • Policy Bind Points – Session Policies can be bound to three different bind points – Citrix Gateway Virtual Server, AAA Groups, and AAA User.
    • When bound to a Citrix Gateway Virtual Server, the Session policy/profile applies to all users that log into that Virtual Server.
    • When bound to a AAA Group, the Session policy/profile only applies to members of the AAA group (Active Directory group or local group)
    • When bound to a AAA User, the Session policy/profile only applies to the AAA user (Active Directory user or local user)
  • Profile Conflicts – Multiple Session Policies/Profiles could apply to a single session. In this case, the Profile settings are merged. But if there’s a conflict (e.g. one Session Profile enables Clientless access, but another Session Profile disables Clientless access), then which one wins?
    • Priority number – When you bind a Session Policy to a bind point, you specify a priority number. This priority number usually defaults to 100.
    • Lowest priority number wins – The Session Policy binding that has the lowest priority number, wins. Session Policies bound with a priority of 80 will win over Session Policies bound with a priority of 100. Remember, for settings that don’t conflict, the two Profiles merge, but for settings that do conflict, the lower priority number policy/profile settings win.
    • Classic Policy Priority and multiple bind points – for Classic Session Policies the bind point location doesn’t matter. If you bind a Session Policy to a AAA Group with a priority of 100, and you also bind a Session Policy to the Citrix Gateway Virtual Server with a priority of 80, then the conflicting settings in the Session Policy bound to the Citrix Gateway Virtual Server will win because it has the lower priority number. You might think that AAA-bound policies always override Virtual Server-bound policies, but that is not the case.
    • Advanced Policy Priority and multiple AAA Groups – see CTX289931 AAA group session policies are not applying based on priority. The first created AAA Group overrides AAA Groups created later unless you specify the weight parameter when creating the AAA Group from the CLI.
  • Global Settings vs Virtual Server Settings – When you bind a Session Policy to a Citrix Gateway Virtual Server, the settings in the Session Profile only apply to connections through that particular Citrix Gateway Virtual Server.
    • Settings in Citrix Gateway > Global Settings > Change Global Settings apply to every Gateway Virtual Server.
    • Settings in AAA Group > Policies > Session Policy/Profile apply to every Gateway Virtual Server.
    • If you want a particular Gateway Virtual Server to override AAA or Global, your only choice is to bind a Session Policy to the Gateway Virtual Server with a lower priority number than the AAA Bind Points.

AAA Groups are a critical component of Citrix Gateway VPN configuration:

  • Group extraction – Make sure the LDAP Policy/Server is configured to extract to the user’s Active Directory Groups.
  • Create AAA Groups on the Citrix ADC that match exactly (case sensitive) with the user’s Active Directory Group Name.
    • Default Syntax and AD Groups – An alternative to AAA Groups is to use HTTP.REQ.USER.IS_MEMBER_OF("MyADGroup") Default Syntax expressions. However, Default Syntax does not support Endpoint Analysis. And Default Syntax only applies to Session Policies and Authorization Policies, so you might still need AAA Groups for Bookmarks, Intranet Applications, and Intranet IPs.
  • You can bind policies and other Gateway objects to the AAA Group, and these bindings only affect that particular AAA Group. These bindings include:
  • If the user belongs to multiple AAA Groups, then policies are applied as follows:
    • Session Policies – the settings are merged, unless there’s a conflict. If a conflict, then the policy with the lowest priority number wins.
    • Bookmarks, Intranet Applications, and Authorization Policies are merged.
    • Intranet IPs (IP Pool) are probably random allocation. It’s probably best to make sure a user only belongs to one AAA Group that assigns Intranet IPs.
  • You can also create local AAA Groups that are unrelated to Active Directory groups. There are several ways of getting users into these local AAA groups:
    • Create local AAA Users and assign them to the AAA Group
    • Configure Session Policy/Profile with a Client Security Check String (EPA Scan). If the scan succeeds, users are placed into local Authorization AAA Groups. If the scan fails, then users are placed into a local Quarantine AAA Group, and removed from all other AAA Groups.
    • When users are authenticated with a particular authentication server, the authentication server can be configured to place users into a Default Authentication Group. This lets you apply different Session Policy/Profiles (and other Gateway objects) depending on how the user authenticated.

Citrix Gateway supports Client Security Expressions (Endpoint Analysis expressions) at four different locations:

  • nFactor (Authentication Virtual Server) Advanced EPA Policy and EPA Action – this is the preferred method in ADC 13 and newer since Classic EPA is supposed to be removed in ADC 13.1 and newer. See nFactor EPA for details.
  • Classic Preauthentication Policy Expression
    • If the EPA Scan succeeds, then the user is allowed to login.
    • If the EPA Scan fails, then the user is not allowed to login.
    • Preauthentication Policies are bound to Citrix Gateway Virtual Servers only, and thus applies to all users of that Virtual Server.
  • Classic Session Policy Expression – Note: Advanced Session Policies do not support EPA expressions. Use nFactor instead.
    • This type of EPA Scan is configured in the Session Policy Expression, not the Session Profile.
    • If the EPA Scan succeeds, then the settings in the Session Profile are applied to the session.
    • If the EPA Scan fails, then the Session Profile is ignored. Other Session Policies expressions are still evaluated. Remember, Session Policy/Profiles merge, so all applicable Session Policies must be considered.
    • A limitation of this EPA method is that nothing negative happens. Instead, you typically design higher priority number (lower priority) Session Policies with restrictive settings so that if the EPA Scans fail, then users still get something. For example, you can configure your highest priority number Session Policy/Profile with StoreFront (ICA Proxy) only. In the lower priority number Session Policies/Profiles, VPN might be enabled, but only if the EPA scan succeeds. More restrictive Session Profiles usually uncheck Client Choices, and enable Clientless Access or ICA Proxy.
    • This method of EPA Scans is used in SmartAccess and SmartControl configurations.
    • EPA expressions are not supported in Default Syntax, so you’ll need to use Classic Syntax instead.
  • Session Profile > Security tab > Advanced Settings > Client Security Check String
    • If the EPA Scan succeeds, add the user to the listed Authorization AAA Groups.
    • If the EPA Scan fails, add the user to the selected Quarantine Group, and remove the user from all other AAA Groups.
    • If Quarantine Group is not defined, then prevent SSL VPN. Other methods of connecting (Clientless, StoreFront), still work.
  • Assigning EPA scans to Session Policies and Session Profiles is also known as Post-Authentication EPA Scans.
  • If Endpoint Analysis is configured anywhere, then an Endpoint Analysis plug-in is downloaded to the Windows or Mac client.

Prerequisites

Gateway Universal Licenses

Except for ICA Proxy, all Citrix Gateway connection methods require a Citrix Gateway Universal License for each concurrent session. Go to System > Licenses.

On the right, make sure Maximum Citrix Gateway User licenses are installed. Most Citrix ADC Editions come with built-in licenses. For example, Citrix ADC Premium Edition comes with Unlimited Gateway licenses.

DNS Name Servers

DNS usually needs to function across the VPN tunnel. Go to Traffic Management > DNS > Name Servers to add DNS servers.

In ADC 13.0 build 71.44 and newer, VPN plug-in for Windows supports Secure DNS update. This feature is disabled by default. To enable it, create the following on the client device: (source = 13.0-71.44 release notes) 💡

  • HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Secure Access Client\secureDNSUpdate value of type REG_DWORD and set it to 1.
    • When you set the value to 1, the VPN plug-in tries the unsecure DNS update first. If the unsecure DNS update fails, the VPN plug-in tries the secure DNS update.
    • To try only the secure DNS update, you can set the value to 2.

AAA Groups

  1. Edit your LDAP Policy/Server, and make sure Group Extraction is configured. Configure the Group Attribute and the Sub Attribute Name. This causes Citrix ADC to extract the user’s AD groups when the user logs in using LDAP.
  2. Go to Citrix Gateway > User Administration > AAA Groups.
  3. On the right, click Add.
  4. Enter a case sensitive group name that matches the group name in Active Directory. Click OK.
  5. On the right, in the Advanced Settings column, you can see the types of objects that can be bound to AAA Groups. These objects are detailed later in this post.

Create Session Profile

To enable SSL VPN: first create the Session Profile. Then create a Session Policy.

You can create multiple Session Policies/Profiles with different settings. Then you can bind these Session Policies to AAA groups and/or Citrix Gateway Virtual Servers. The Session Profiles are merged, and if conflicts, lower priority bind points win.

To enable SSL VPN in a Session Profile:

  1. On the left, expand Citrix Gateway, expand Policies, and click Session.
  2. On the right, switch to the Session Profiles tab, and click Add.
  3. Name the profile VPN or similar.
  4. In Session Profiles, every field has an Override Global checkbox to the right of it. If you check this box next to a particular field, then you can configure that field, and the field in this session profile will override settings configured globally (Citrix Gateway > Global Settings > Change Global Settings), or in a lower priority (higher priority number) session policy.

Network Configuration tab

  1. In the Session Profile, switch to the Network Configuration tab.
  2. You will find a setting that lets you select a DNS Virtual Server. Or if you don’t select anything, then the tunnel will use the DNS servers configured under Traffic Management > DNS > Name Servers.

Client Experience Tab

  1. In the Session Profile, switch to the Client Experience tab. This tab contains most of the Citrix Gateway VPN settings.
  2. Override Plug-in Type, and set it to Windows/Mac OS X.
  3. On the Client Experience tab, override Split Tunnel and make your choice. Setting it to OFF will force all traffic to use the tunnel. Setting it to ON will require you to create Intranet Applications so the Citrix Gateway Plug-in will know which traffic goes through the tunnel, and which traffic goes directly out the client NIC (e.g. to the Internet). REVERSE means all traffic goes through the tunnel except for the addresses defined in Intranet Applications.
  4. On the Client Experience tab, there are timers that can be configured. Global Settings contains default timers, so you might want to configure this Session Profile to override the defaults and increase the timeouts. See Configuring Time-Out Settings at Citrix Docs for details.
    1. Client Idle Time-out is a Citrix Gateway Plug-in timer that disconnects the session if there is no user activity (mouse, keyboard) on the client machine.
    2. Session Time-out is a Citrix Gateway timer that disconnects the session if there is no network activity for this duration.
    3. In addition to these two timers, on the Network Configuration tab, under Advanced Settings…
    4. There’s a Forced Timeout setting.
  5. By default, once the VPN tunnel is established, a portal page appears containing Gateway Bookmarks, and StoreFront published icons. An example of the portal page in the RfWebUI theme is shown below:

    1. The X1 theme is shown below:
  6. On the Client Experience tab, the Home Page field lets you override the the default portal page, and instead display a different webpage (e.g. Intranet). This homepage is displayed after the VPN tunnel is established (or immediately if connecting using Clientless Access).
  7. Citrix Gateway can automatically start the VPN tunnel whenever the user is remote. This method only starts the VPN Tunnel after the user is logged into Windows.
    1. On the Client Experience tab, click the plus icon next to AlwaysON Profile Name.
    2. Give the profile name. Hover over the question marks to see what each of them does.
    3. Then click Create.
    4. More info at AlwaysON at Citrix Docs.
  8. Citrix Gateway 12.1 build 51 and newer also support the VPN Client establishing a tunnel before the user logs into Windows. The pre-logon AlwaysOn Service feature requires certificate-based authentication and registry keys on the client device. See AlwaysOn service for Windows at Citrix Docs. 💡
  9. Additional VPN settings can be found by clicking Advanced Settings near the bottom of the Client Experience tab.
  10. Under Client Experience > Advanced Settings, on the General tab, there are settings to run a login script at login, enable/disable Split DNS, and enable Local LAN Access. Use the question marks to see what they do.
  11. Note: if Split Tunnel is OFF, and if Split DNS is set to REMOTE, Citrix Gateway only returns one IP address to DNS queries. This behavior can be changed by following Citrix CTX200243 DNS Query Responds with Only One IP to Client PC When Connected Through NetScaler Gateway Full VPN.
  12. Under Client Experience > Advanced Settings, on the General tab, is a checkbox for Client Choices. This lets the user decide if they want VPN, Clientless, or ICA Proxy (StoreFront). Without Client Choices, one of the connection methods will occur automatically, depending on what’s enabled.
  13. An example of Client Choices is shown below:

    • On the main Client Experience tab, if you enabled Client Choices, you can set Clientless Access to Off to add Clientless to the list of available connection methods in the Client Choices screen.
    • Clientless Access is difficult to remove from the Client Choices page since you need Clientless Access for StoreFront integration. The following removal instructions were confirmed on a custom Portal Theme based on RfWebUI:
      1. WinSCP to the Citrix ADC.
      2. Navigate to /var/netscaler/logon/themes/<yourThemeName>/css.
      3. Edit the file theme.css.
      4. At the bottom of the file, add the following code: (source = CTP Sam Jacobs at NetScaler Gateway Client Choices – hide/remove Virtual Apps and Desktops at Citrix Discussions. 
        div.box:nth-child(2) {
 display:none;
}
      5. When you refresh the Client Choices page, the Clientless box should be hidden.
  14. The Client Experience > Advanced Settings section has additional tabs. A commonly configured tab is Proxy, which allows you to enable a proxy server for VPN users.

Security Tab

  1. Back in the main Session Profile, switch to the Security tab.
  2. Set the default authorization to Allow or Deny. If Deny (recommended), you will need to create authorization policies to allow traffic across the tunnel. You can later create different authorization policies for different groups of users.

Published Applications Tab

  1. On the Published Applications tab, set ICA Proxy to Off. This ensures VPN is used instead of ICA Proxy.
  2. Configure the Web Interface Address to embed StoreFront into the default Clientless Access portal page.
    • Note: for X1 theme, additional iFrame configuration is required on the StoreFront side as detailed below. RfWebUI theme does not need any StoreFront changes.
    • From Michael Krasnove: if you configured the Session Policy to direct users to StoreFront, but aren’t using RfWebUI, then placing the following code in c:\inetpub\wwwroot\Citrix\StoreWeb\custom\script.js will cause StoreFront to end the VPN tunnel when the user logs off of StoreFront. 
      var LOGOFF_REDIRECT_URL = 'https://YourGatewayFQDN.com/cgi/logout';
 
// Prevent the default "logoff" screen from being displayed
CTXS.Controllers.LogoffController.prototype._handleLogoffResult = $.noop;
 
CTXS.Extensions.afterWebLogoffComplete = function () {
 window.location.href = LOGOFF_REDIRECT_URL;
};
  3. See the ICA Proxy post for more information on integrating StoreFront with Citrix Gateway.

Other Tabs

  1. The Remote Desktop tab is detailed in the RDP Proxy post.
  2. The PCoIP tab is detailed in the PCoIP Proxy post.
  3. Click Create when you’re done creating the Session Profile.

Create Session Policy

Once the Session Profile is created, you need a Session Policy linked to it. The Session Policy contains an expression, where if true, then the Session Profile is applied.

If multiple Session Policies apply to a particular connection, then the settings in the policies are merged. For conflicting settings, the Session Policy with the highest priority (lowest priority number) wins. Session Policies bound to AAA groups only override Session Policies bound to Citrix Gateway Virtual Servers if the AAA group bind point has a lower priority number. In other words, priority numbers are evaluated globally no matter where the Session Policy is bound. You can run the command nsconmsg –d current –g pol_hits to see which Session Policies are applying to a particular connection. See CTX214588 Understanding Session Policy Priority on Different Bind Points.

You can also include Endpoint Analysis expressions in a Session Policy, so that the Session Policy only applies to machines that pass the Endpoint Analysis scan. However, EPA Scans are only supported with Classic Syntax policy expressions, and not with Default Syntax.

To create a Session Policy that is linked to a Session Profile:

  1. On the left, go to Citrix Gateway > Policies > Session.
  2. In the right pane, switch to the Session Policies tab, and click Add.
  3. Give the policy a descriptive name.
  4. Change the Profile drop-down to the VPN Profile you just created.
  5. The Expression box has an option for switching to Default Syntax.

    1. If Default Syntax, enter true in the Expression box so it always evaluates to true. If Classic Syntax, it would be ns_true instead of true.
    2. If Default Syntax, you can enter HTTP.REQ.USER.IS_MEMBER_OF("MyADGroup") to restrict the Session Profile to members of a specific AD group. In Classic Syntax, this isn’t possible in an expression, and instead you must assign the Session Policy to a AAA Group.
  6. If Classic Syntax, you can add Endpoint Analysis scans to the Expression box. If the Endpoint Analysis scan succeeds, then the session policy is applied. If the Endpoint Analysis scan fails, then this session policy is skipped, and the next one is evaluated. This is how you can allow VPN if EPA scan succeeds, but all failed EPA scans will get a different session policy that only has ICA Proxy enabled.
    1. To add an Endpoint Analysis scan, use one of the Editor links on the right.
    2. Configure OPSWAT scans in the OPSWAT EPA Editor.
    3. Configure Client Security Expressions in the Expression Editor.
    4. You can combine multiple Endpoint Analysis scan expressions using Booleans (&&, ||, !).
  7. Click Create when done.

Bind Session Policy

Most of the Citrix Gateway configuration objects can be bound to a Citrix Gateway Virtual Server, AAA Groups, or both. This section details binding of Session Policies, but the other Citrix Gateway objects (e.g. Authorization Policies) can be bound using similar instructions.

  • Objects bound directly to the Citrix Gateway Virtual Server are evaluated for every user of that Gateway Virtual Server.
  • Objects bound to a AAA Group are only evaluated for members of that AAA Group.
    • Polices bound to AAA Groups usually have lower priority numbers than policies bound to Gateway Virtual Servers, so the AAA binding can override the Gateway binding.
    • However, objects/policies bound to a AAA Group are applied to every Gateway Virtual Server on the same appliance. To override AAA bindings at a specific Gateway, you can bind lower priority number policies to the Gateway Virtual Server.

Bind the new Session Policy to a Citrix Gateway Virtual Server, or a AAA group.

To bind to a Citrix Gateway Virtual Server

  1. Edit a Citrix Gateway Virtual Server (or create a new one).
  2. To make sure ICA Only is unchecked:
    1. Click the pencil icon for the Basic Settings section.
    2. Click More.
    3. Make sure ICA Only is unchecked, and click OK to close the Basic Settings section.
    4. Note: with this box unchecked, Gateway Universal licenses are now required for all users connecting through this Gateway Virtual Server.
  3. While editing the Gateway Virtual Server, consider changing the Portal Theme to RfWebUI. This changes the default portal page to look identical to StoreFront.
  4. Scroll down to the Policies section, and click the Plus icon.
  5. In the Choose Type page, ensure the Choose Policy drop-down is set to Session.
  6. Ensure the Choose Type drop-down is set to Request, and click Continue.
  7. Click where it says Click to select.

    1. If you already have Session Policies bound to this Gateway Virtual Server, then you might have to click Add Binding first.
  8. Click the radio button next to the previously created Session Policy, and click Select.
  9. Note: you cannot mix Classic Syntax Policies and Default Syntax Policies.
  10. In the Priority field, adjust the priority number. If you want this Session Policy to override other Session Policies, then set the priority number to a low value. See CTX214588 Understanding Session Policy Priority on Different Bind Points.
  11. Click Bind.
  12. If you already have Session Policies bound to the Gateway Virtual Server, then the list of Policies is displayed. If you don’t see this list, on the left, in the Policies section, click the line that says Session Policies.
  13. From this list, you can right-click the policies to Edit Binding (priority number), or Edit Profile.
  14. If your Citrix Gateway Virtual Server is configured with a Traffic Policy for Native OTP (One Time Passwords), change the Traffic Policy expression to the following. Source = Julien Mooren at NetScaler – Native OTP is breaking SSL VPN. 
    http.req.method.eq(post)||http.req.method.eq(get) && false

Bind to AAA Group

  1. To bind to a AAA Group, go to Citrix Gateway > User Administration > AAA Groups.
  2. On the right, add a AAA group with the same name (case sensitive) as the Active Directory group name. This assumes your LDAP policies/server are configured for group extraction (Group Attribute, and Sub Attribute).
  3. Edit the AAA Group.
  4. On the right, in the Advanced Settings column, add the Policies section.
  5. Click the plus icon to bind one or more Session Policies.
  6. If you want these Session Policies to override the Session Policies bound to the Citrix Gateway Virtual Server, then make sure the Session Policies bound to the AAA Group have lower priority numbers. See CTX214588 Understanding Session Policy Priority on Different Bind Points.


  7. If a user belongs to multiple groups, then for Advanced Session Policies, see CTX289931 AAA group session policies are not applying based on priority. Classic Policies in multiple AAA Groups are lumped together and evaluated based on bind point priority number. Advanced Policies are no longer lumped together and instead each AAA Group is evaluated separately. The first AAA Group created has higher priority than later created AAA Groups unless you specify the weight when creating the AAA Group from the CLI. 💡

Citrix Gateway Plug-in

Upgrade Citrix Gateway Plug-in

Citrix ADC pushes the Gateway Plug-in (aka VPN client) to client machines. In newer builds of Citrix ADC 13.0, you can upgrade the VPN plugin on the ADC without upgrading the ADC firmware.

  1. Download the latest plugin .tgz file from https://www.citrix.com/downloads/citrix-gateway/plug-ins/citrix-gateway-windows-plug-in-clients.html.
  2. In Citrix ADC, on the left click the Citrix Gateway node. On the right, click Upgrade EPA Libraries or EPA/VPN plugins.
  3. This page shows you the versions of the currently installed plugins.
  4. Click Choose File and select the win_vpn.tgz file. Click Upgrade.
  5. Click OK when prompted that the upgrade completed successfully.
  6. Go back to the Upgrade plug-in or EPA Libraries page to see the new versions.

Citrix Gateway Plug-in Installation

Here is what the user sees when launching the VPN session for the first time. This assumes the user is an administrator of the local machine.

  1. Wait for 10 seconds for the webpage to not detect Gateway Plug-in, and then click the Download button.
  2. Run the downloaded AGEE_setup.exe.
  3. In the Please read the Citrix Gateway Plug-in License Agreement page, click Install.
  4. In the Complete the Citrix Gateway Plug-in Setup Wizard page, click Finish.
  5. Click Yes to restart your system.
  6. In ADC 13.0 build 71.44 and newer, VPN plug-in for Windows supports Secure DNS update. This feature is disabled by default. To enable it, create the following on the client device: (source = 13.0-71.44 release notes) 💡
    • HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Secure Access Client\secureDNSUpdate value of type REG_DWORD and set it to 1.
      • When you set the value to 1, the VPN plug-in tries the unsecure DNS update first. If the unsecure DNS update fails, the VPN plug-in tries the secure DNS update.
      • To try only the secure DNS update, you can set the value to 2.

Only administrators can install the Citrix Gateway Plug-in. You can download the Gateway plug-in from the NetScaler appliance at /var/netscaler/gui/vpns/scripts/vista and push it to corporate-managed machines. Or you can download VPN clients from Citrix.com. The VPN client version must match the Citrix ADC firmware version.

To deploy the Gateway Plug-in using Group Policy, see CTX124649 How to Deploy NetScaler Gateway Plug-in and Endpoint Analysis Installer Packages for Windows by Using Active Directory Group Policy.

While a VPN tunnel is established, you can open the Gateway Plug-in to see status. If the Gateway Plug-in is merged with Workspace app, right-click Workspace app, click Advanced Preferences, click Citrix Gateway Settings, and click Open.

Or, if the Gateway Plug-in icon is separated from Workspace app, then right-click the Gateway Plug-in icon, and click Open.

The hamburger menu on the left lets you see more info about the VPN tunnel.

If the Gateway VPN session isn’t established, you can open the Gateway plug-in, and login. No browser needed.

  • Gateway Plug-in 12.1 build 49 with Citrix ADC 12 build 49 support nFactor authentication (e.g. Native OTP) in the Gateway Plug-in. Older versions do not support nFactor.  💡

The Configuration page lets you enable Logging. Then the Logging page lets you collect the logs. See Citrix CTX138155 How to Collect Client VPN Logs for NetScaler Gateway.

VPN Client (Citrix Gateway Plug-in) Session Profile Settings

Separate Icons for Workspace app and Gateway

  1. By default, if Workspace app, and Citrix Gateway Plug-in, are installed on the same machine, then the icons are merged. To see the Citrix Gateway Plug-in Settings, you right-click Workspace app, open Advanced Preferences, and then click Citrix Gateway Settings. This makes it difficult to log off.

  2. You can configure the Session Profile to prevent the Citrix Gateway Plug-in from merging with Workspace app. Edit your VPN Session Policy/Profile. On the Client Experience tab…
  3. Scroll down, and check the box next to Advanced Settings.
  4. At the bottom of the General tab, check the box next to Show VPN Plugin-in icon with Receiver.
  5. This setting causes the two icons to be displayed separately thus making it easier to access the Citrix Gateway Plug-in settings, including Logoff.

Cleanup

  1. When the user logs off of VPN, a Cleanup page is displayed. This can be enabled or disabled in a Session Profile on the Client Experience tab.

  2. The cleanup options can be forced in a Session Profile on the Client Experience tab…
  3. Under Advanced Settings > Client Cleanup.

VPN Client Upgrades

  1. Whenever Citrix ADC firmware is upgraded, all users will be prompted to upgrade their VPN clients. You can edit a Session Policy/Profile, and on the Client Experience tab…
  2. Use the Upgrade drop-downs to disable the automatic upgrade.
  3. The Plugin Upgrade settings are also configurable in the Gateway Virtual Server…
  4. In the Basic Settings > More section.


Authorization Policies

If your Session Profile has Security tab > Default Authorization Action set to Deny (recommended), then create Authorization Policies to allow access across the tunnel.

  1. On the left, under Citrix Gateway, expand Policies, and click Authorization.
  2. On the right, click Add.
  3. Name the Authorization Policy.
  4. Select Allow or Deny.
  5. For the Expression, Citrix Gateway supports both Classic Syntax and Default Syntax.
    • Default Syntax gives you much greater flexibility in matching the traffic that should be allowed or denied. Hit Control+Space on your keyboard to begin building a Default Syntax expression. You typically want to identify traffic based on Destination IP Address, Destination Port Number, HTTP Request URL, HTTP Host Header, etc. Common expressions include:
      • CLIENT.IP.DST.IN_SUBNET()
      • CLIENT.TCP.DSTPORT.EQ()
      • You can also use HTTP.REQ.USER.IS_MEMBER_OF("MyADGroup") in your expressions.
    • CTX232237 NetScaler Unified Gateway Advanced Authorization Policy Support for UDP/ICMP/DNS Traffic explains new types of Authorization Policies in NetScaler 12.0 build 56 and newer.
      • CLIENT.UDP.DSTPORT.EQ(2080)
      • CLIENT.IP.PROTOCOL.EQ(ICMP)
      • CLIENT.UDP.DNS.DOMAIN.CONTAINS("citrix")
    • Note: you cannot mix both Classic Syntax and Default Syntax. You must unbind every Classic Syntax Authorization Policy before you can bind Default Syntax Authorization Policies.
  6. Click Create when done.
  7. Authorization Policies are usually bound to AAA groups. This allows different groups to have different access across the tunnel.
    1. Or, you can use HTTP.REQ.USER.IS_MEMBER_OF("MyADGroup") in your Default Syntax expressions.
  8. Edit a AAA Group at Citrix Gateway > User Administration > AAA Groups.
  9. On the right, in the Advanced Settings column, add the Authorization Policies section.
  10. Then click where it says No Authorization Policy to bind policies.

Intranet Applications

If you enabled Split Tunnel, then you’ll need to create Intranet Applications to specify which traffic goes through the tunnel.

  1. On the left, under Citrix Gateway, expand Resources, and click Intranet Applications.
  2. On the right, click Add.

    1. Enter a name for the Internal subnet.
    2. Change the Interception Mode to TRANSPARENT.
    3. Enter an IP subnet. Only packets destined for this network go across the tunnel.
      1. You typically specify a summary address for all internal subnets (e.g. 10.0.0.0/8).
      2. Alternatively, you can define minimal Intranet Application destinations as a security mechanism (assuming Split Tunnel is enabled), but Authorization Policies are more appropriate for that task.
  3. Click Create.
  4. Create additional Intranet applications for each internal subnet.
  5. Intranet Applications are usually bound to the Gateway Virtual Server, but you can also bind them to AAA Groups.
  6. On the right, in the Advanced Settings column, add the Intranet Applications section.
  7. On the left, click No Intranet Application to bind Intranet Applications.

DNS Suffix

Specify a DNS Suffix for Split DNS to function with single label DNS names. Citrix Gateway adds these DNS suffixes to DNS queries across the VPN tunnel.

  1. On the left, under Citrix Gateway, expand Resources, and click DNS Suffix.
  2. On the right, click Add.
  3. Enter the DNS Suffix, and click Create. You can add multiple suffixes.

Bookmarks

Bookmarks are the links that are displayed in the default portal interface. They can point to websites, or RDP addresses. PCoIP bookmarks come from VMware Horizon Connection Server. ICA bookmarks come from Citrix StoreFront.

  1. Under Citrix Gateway, expand Resources, and click Bookmarks.
  2. On the right, click Add.

    1. Give the bookmark a name, and display text.
    2. Enter a website or RDP address.
    3. Optionally browse to an Icon file.
    4. You typically need to check Use Citrix Gateway As a Reverse Proxy, especially for Clientless Access (rewrite without VPN) to an internal website.
    5. The other fields are for Single Sign-on through Unified Gateway.
  3. Click Create.
  4. Bookmarks (aka Published Applications > Url) are usually bound to AAA groups so different groups can have different bookmarks. But it’s also possible to bind Bookmarks to Citrix Gateway Virtual Servers.
  5. If Citrix Gateway Virtual Server, add the Published Applications section to bind Bookmarks (Url).
  6. For AAA Group, it’s the Bookmarks section.
  7. On the left, find the Published Applications section, and click No Url to bind Bookmarks.

VPN Client IP Pools (Intranet IPs)

By default, Citrix Gateway VPN clients use Citrix ADC SNIP as their source IP when communicating with internal resources. To support IP Phones or endpoint management, you must instead assign IP addresses to VPN clients.

Any IP pool you add to Citrix Gateway must be reachable from the internal network. Configure a static route on the upstream router. The reply traffic to VPN Client IPs should be routed through a Citrix ADC SNIP. Or the Citrix ADC can participate in OSPF.

When a client is assigned a client IP, this IP address persists across multiple sessions until the appliance reboots, or until the appliance runs out of IPs in the pool.

  1. Edit a Citrix Gateway Virtual Server, or a AAA group.
  2. On the right, in the Advanced Settings section, click the plus icon next to Intranet IP Addresses.
  3. On the left, click where it says No Intranet IP.
  4. Enter a subnet and netmask. Click Bind.
  5. In a Session Profile, on the Network Configuration tab, check the box next to Advanced Settings.
  6. Use the Intranet IP drop-down to configure the behavior when there are more VPN clients than available IPs in the address pool.

    1. If you set it to NOSPILLOVER, then users can only have one VPN session, as described in CTX218066 How to Limit One Session Per User on NetScaler Gateway?.


  7. To see the Client IP address, on the client side, after the tunnel is established, right-click the Citrix Gateway Plug-in, and click Open.
  8. See the Internal network address.
  9. To see the client IP on the Citrix ADC, go to Citrix Gateway, and on the right is Active user sessions.
  10. Select one of the views, and click Continue.
  11. The right column contains the Intranet IP.

StoreFront in Gateway Clientless Access Portal

If you enabled the RfWebUI theme, then no StoreFront configuration is necessary.

But if you want to embed StoreFront in the other Gateway themes (X1, Default, Green Bubble), then follow these instructions.

  1. On StoreFront, edit the file C:\Inetpub\wwwroot\Citrix\StoreWeb\web.config.
    1. On the bottom, there are three sections containing X-Frame-Options. Change all three of them from deny to allow.
    2. Also change frame-ancestors from none to self.
  2. In Citrix ADC, go to Citrix Gateway > Global Settings, and click Configure Domains for Clientless Access.
  3. Change the selection to Allow Domains, enter your StoreFront FQDN, and click the plus icon.
  4. Click OK.
  5. In a Session Policy/Profile:
    1. On the Client Experience tab, make sure Single Sign-on to Web Applications is enabled.
    2. On the Published Applications tab, configure the Web Interface Address to point to the StoreFront Receiver for Web page.
    3. Configure the Single Sign-on domain to match what’s configured in StoreFront.
    4. You might have to override the Web Interface Portal Mode.
  6. The Applications page of the 3-page portal (e.g. X1 theme) should automatically show the StoreFront published icons.

Quarantine Group

Citrix Gateway can be configured so that if Endpoint Analysis scans fail, then the user is placed into a Quarantine Group. You can bind session policies, authorization policies, etc. to this quarantine group. Policies bound to other AAA groups are ignored.

  1. Go to Citrix Gateway > User Administration > AAA Groups.

    1. Add a new local group for your Quarantined Users. This group is local, and does not need to exist in Active Directory.
    2. Bind session policies, authorization policies, etc. to your quarantine AAA group. These policies typically allow limited access to the internal network so users can remediate. Or, it might simply display a webpage telling users how to become compliant.
    3. The Session Policy bound to the Quarantine Group is usually different than the Session Policies bound to other AAA groups. You can use the variation in Session Policy names for SmartAccess.
      1. One option is to configure the Delivery Groups > Access Policy so that icons are shown for Session Policies bound to non-quarantine AAA Groups, but not for the Session Policy that is bound to the Quarantine Group.
      2. Another option is to configure Citrix Policies > Access Control to disable functionality for the Quarantine Group Session Policy, but not for other AAA Group Session Policies.
  2. Create or edit a Session Profile to include a Client Security Expression that checks for compliance.
    1. In the Session Profile, on the Security tab, check the box next to Advanced Settings.
    2. Scroll down, and check the box to the right of Client Security Check String.
    3. Use the Editor links to add an Endpoint Analysis expression.
    4. Just below the Client Security Check String, select the previously created Quarantine Group. If the Client Security Check String EPA Scan fails, then the failed users are added to the Quarantine Group and removed from all other AAA Groups.
  3. Click Create when done creating or editing the Session Profile.
  4. Create a Session Policy for the Session Profile that contains the Client Security Check String.
    1. Enter ns_true as the expression.
    2. Then click Create.
  5. Edit your Gateway Virtual Server, and bind the Session Policy/Profile that has the Client Security Check String configured.


  6. To troubleshoot Quarantine policies, use the command nsconmsg –d current –g pol_hits.
  7. Citrix ADM Gateway Insight shows users that failed EPA scans, and their quarantine status.

Related Pages

RDP Proxy – Citrix Gateway

Last Modified: Apr 16, 2021 @ 2:23 pm

91 Comments

This article applies to Citrix Gateway 13.0, Citrix Gateway 12.1, and NetScaler Gateway 12.0. Citrix ADC is the new name for NetScaler. Citrix Gateway is the new name for NetScaler Gateway.

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💡 = Recently Updated

Change Log

RDP Proxy Overview

Citrix ADC supports RDP Proxy through Citrix Gateway. No VPN required. RDP can connect through Citrix Gateway on port 443.

There are several ways of launching RDP sessions through Citrix Gateway RDP Proxy:

  • Bookmarks on the Clientless Access portal page.
    • Bookmarks can be defined by the administrator.
    • Or users can add their own RDP bookmarks.
  • After logging in, change the URL in the browser to /rdpproxy/MyRDPServer. MyRDPServer can be IP or DNS.
  • In the RfWebUI Portal Theme, the Bookmark link lets users enter an RDP address, and click Go.

Links:

Requirements

Here are some requirements for RDP Proxy:

  • Citrix ADC Advanced Edition or Premium Edition.
    • Citrix Gateway Enterprise VPX is not sufficient. It must be a full ADC license.
  • Citrix Gateway Universal Licenses for each user.
    • Most Citrix ADC Editions come with built-in Gateway Universal licenses: Citrix ADC Standard Edition = 500 licenses, Citrix ADC Advanced Edition = 1000 licenses, and Citrix ADC Premium Edition = unlimited licenses. See Feature Licensing in the Gateway Tweaks post.
  • TCP 443 opened to the Citrix Gateway Virtual Server.
  • TCP 3389 opened from the Citrix ADC SNIP to the RDP Servers.

Configuration

Enable RDP Proxy Feature

  1. Go to System > Settings, and click Configure Advanced Features.
  2. In the left column, near the bottom, check the box for RDP Proxy and click OK.

Create RDP Server Profile

You do not need a RDP Server Profile if the machines you want to RDP to are not members of any RDS Connection Broker Infrastructure. Skip to the next section to create the RDP Client Profile.

If you want Citrix Gateway to RDP Proxy to a RDSH machine that is part of an RDS Connection Broker Infrastructure (aka RDS Collection, or member of RDS Broker Farm), then you’ll need the following:

  • Citrix ADC 12.1 or newer
    • NetScaler 12.0 does not support RDSH machines connected to RDS Connection Broker.
  • RDP Server Profile to enable the 3389 listener on your Gateway Virtual Server.

RDP connections through Citrix Gateway to RDP Connection Broker members requires that the Remote Desktop Session Hosts are configured to disable the GPO setting Use IP Address Redirection located in a GPO at Computer Configuration | Policies | Administrative Templates | Windows Components | Remote Desktop Services | Remote Desktop Session Host | RD Connection Broker. Disable this setting on the RDSH machines, not the Connection Broker machine. Disabling this setting enables token-based redirection instead of IP-based redirection, which is required by RDP Proxy in Citrix Gateway.

To create the RDP Session Profile on Citrix ADC:

  1. Expand Citrix Gateway, expand Policies, and click RDP.
  2. On the right, on the Server Profiles tab, click Add.
  3. In the Create RDP Server Profile window:
    1. Give the RDP Server Profile a name.
    2. If you don’t enter an RDP IP, then it will use the Gateway VIP.
    3. If you don’t enter a RDP Port, then it will default to 3389. This is an additional port that must be opened on the firewall.
    4. Enter a new Pre Shared Key.
    5. Change RDP Redirection to ENABLE. This is a new feature in ADC 12.1. This setting enables RDS Infrastructure to work.
  4. Click Create.

Create RDP Proxy Client Profile

All RDP Proxy configurations need an RDP Client Profile.

  1. Expand Citrix Gateway, expand Policies, and click RDP.
  2. On the right, switch to the Client Profiles tab, and click Add.

    1. Give the RDP Client Profile a name, and configure the client device mappings as desired. Scroll down.
    2. For the RDP Cookie Validity field, Citrix CTX233207 says that after a HA failover, RDP Proxy session will not reconnect if the cookie has expired.
    3. If you are running ADC 12.1 or newer and need to allow RDP connections to RDS Infrastructure member machines, then enter the same Pre Shared Key that you configured in the RDP Server Profile. If you don’t need to RDP to any member of any RDS Infrastructure, then you don’t need these settings.
      • Also, for RDP Host, enter the FQDN of the Gateway Virtual Server. This is only needed for RDP Server Profiles.
    4. Click Create.

Create RDP Bookmarks

You can create administrator-defined bookmarks that can be assigned to everybody or can be assigned to specific Active Directory groups. Another option is to let each user create their own bookmarks.

  1. On the left, expand Citrix Gateway, expand Resources, and click Bookmarks.

  2. On the right, click Add.

    1. Give the Bookmark a name.
    2. For the URL, enter rdp://MyRDPServer using IP or DNS (FQDN).
      • For RDS Collections, enter the address of any RDP member of the collection. The RDP server will ask the Connection Broker to load balance across the Collection and then redirect the RDP connection to the least busy RDP server in the Collection.
      • For RemoteApp, see Citrix Discussions. Example URL: 
        rdp://rdshost1.comtoso.com?alternate shell:s:||win32calc&remoteapplicationprogram:s:||win32calc&remoteapplicationname:s:Calculator&remoteapplicationcmdline:s:&remoteapplicationmode:i:1
    3. Check the box next to Use Citrix Gateway As a Reverse Proxy,
  3. Click Create.
  4. Create more bookmarks as desired.

Edit a Session Profile

  1. Create or edit a Gateway Session Profile (Session Profiles tab).
  2. On the Security tab, set Default Authorization Action to ALLOW. Or you can use Authorization policies to control access.

  3. On the Remote Desktop tab, check Override Global, and select the RDP Client Profile you created earlier.
  4. On the Client Experience tab, set Clientless Access to On. This enables the clientless access portal that can display administrator-defined bookmarks and lets users add their own bookmarks.
  5. On the Client Experience tab of the Session Profile, decide if you want Single Sign-on to Web Applications or not. It’s required for RDS Collections but optional for RDP machines that are not members of an RDS Infrastructure. If not checked then the user will be prompted to login again when launching an RDP session.
  6. On the Published Applications tab, make sure ICA Proxy is OFF so the clientless portal is displayed.
  7. Click OK when done.

Edit Citrix Gateway Virtual Server

  1. Edit or Create your Gateway Virtual Server.
  2. In the Basic Settings section, click the pencil icon on the top right to edit it.
  3. Click More to show more settings.

    1. If the machines you are RDPing to are not members of an RDS Collection, then don’t configure RDP Server Profile. With no RDP Server Profile configured the RDP connections will be 443 to the Gateway. If you instead configure an RDP Server Profile then the RDP Connections will be 3389 or whatever port number you put in the RDP Server Profile.
    2. If you want to allow RDP to RDS Collection members, then select the RDP Server Profile that you created earlier. The RDP Server Profile enables port 3389 on the Gateway VIP. If you don’t select a RDP Server Profile, then RDP is proxied through 443 on the Gateway, but this won’t work for RDS Collection members.
    3. Scroll down. Make sure ICA Only is not checked. This means you’ll need Citrix Gateway Universal licenses for each user that connects through this Gateway.
    4. Click OK to close the Basic Settings section.
  4. Bind a certificate.
  5. Bind authentication policies.
  6. In the Policies section, bind the Session Policy that has the RDP Client Profile configured. Be mindful of policy priority.


  7. You can bind RDP Bookmarks to either the Citrix Gateway Virtual Server, or to a AAA group. To bind to the Citrix Gateway Virtual Server, on the right, in the Advanced Settings section, click Published Applications.
  8. On the left, in the Published Applications section, click where it says No Url.
  9. Bind your Bookmarks.
  10. While editing your Gateway vServer, you can also set the Portal Theme to RfWebUI. This is strongly recommended for the clientless access portal that displays the RDP bookmarks.

Configure DNS

  1. If you want to connect to RDP servers using DNS, make sure DNS servers are configured on the appliance (Traffic Management > DNS > Name Servers).
  2. If you want to use the short names instead of FQDNs, add a DNS Suffix (Traffic Management > DNS > DNS Suffix).

Use RDP Proxy

  1. Connect to your Citrix Gateway and login.
  2. If you configured Bookmarks, if RfWebUI theme, on the Apps tab, click Web and SaaS Apps.

    1. If X1 theme, the bookmarks are on the Web Apps page.
  3. If RfWebUI theme, you can click Details to mark the Bookmark as a Favorite.

  4. Or you can change the address bar to /rdpproxy/MyRDPServer. You can enter an IP address (e.g. rdpproxy/192.168.1.50) or a DNS name (/rdpproxy/myserver).
  5. If you edit the downloaded .rdp file, notice that it’s connecting on port 443.
  6. Then open the downloaded .rdp file.
  7. You can view the currently connected RDP users by going to Citrix Gateway > Policies > RDP, and on the right is the Connections tab.

Personal Bookmarks

  1. If using the RfWebUI theme, another way to launch RDP sessions is to click the Bookmark link, enter a destination DNS/IP, check the box next to RDP Link, and click Go.
  2. You can also give the Bookmark a name and Save it.
  3. Then access the saved bookmark from Apps > Personal Bookmarks.

  4. Personal bookmarks are stored in /var/vpn/bookmark on the appliance. You might want to back these up and replicate them to other Gateway appliances participating in GSLB. See NetScaler 11.1 Personal Bookmarks at Citrix Discussions.
  5. The X1 theme has an Add button on the Web Apps page.
  6. But there is no Go button. Instead, you save the Bookmark and launch it from the list.

SmartAccess / SmartControl – Citrix Gateway

Last Modified: Aug 3, 2024 @ 9:39 am

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This article applies to NetScaler Gateway 14.1, Citrix Gateway 13.x, Citrix Gateway 12.1, and NetScaler Gateway 12.0.

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SmartAccess / SmartControl

SmartAccess and SmartControl let you change ICA connection behavior (e.g. disable client device mappings, hide icons) based on how users connect to Citrix Gateway. Decisions are based on Citrix Gateway Virtual Server name, Session Policy name, and Endpoint Analysis scan success or failure.

SmartAccess vs SmartControl:

  • SmartAccess lets you control visibility of published icons, while SmartControl does not.
  • SmartControl is configured exclusively on Citrix Gateway, while SmartAccess requires configuration on both Citrix Gateway, and inside Citrix Studio.
  • SmartControl requires Citrix ADC Premium Edition licensing, while SmartAccess is available in all Citrix ADC Editions.
    • Both features require Citrix Gateway Universal licenses for every concurrent connection.

Prerequisites

Both SmartAccess and SmartControl have the same prerequisites. You can configure SmartAccess in Citrix Virtual Apps and Desktops (CVAD) at any time, but it won’t work, until you do the following:

  1. Citrix ADC appliance license: See Feature Licensing in the Gateway Tweaks post. In summary:
    • SmartAccess is available in all editions of Citrix ADC appliances.
    • SmartControl is available only in Citrix ADC Premium Edition.
  2. Citrix Gateway Universal Licenses – On the Citrix ADC, go to System > Licenses, and make sure you have Citrix Gateway Universal Licenses allocated to the appliance.
    1. Most Citrix ADC Editions (except Citrix Gateway Enterprise VPX) come with built-in Gateway Universal licenses: Citrix ADC Standard Edition = 500 licenses, Citrix ADC Advanced Edition = 1,000 licenses, and Citrix ADC Premium Edition = unlimited licenses.
    2. Additional Citrix Gateway Universal licenses can be acquired through other means. See Feature Licensing in the Gateway Tweaks post for details.
    3. The Universal licenses are allocated to the hostname of the appliance (click the gear icon to change it), not the MAC address. In a High Availability pair, if each node has a different hostname, then you can allocate the licenses to one hostname, then reallocate to the other hostname. See Feature Licensing in the Gateway Tweaks post for details.
  3. Citrix Gateway must have ICA Only unchecked.
    1. On the Citrix ADC, go to Citrix Gateway > Virtual Servers, and edit your Gateway Virtual Server.
    2. In the Basic Settings section, click the pencil icon.
    3. Click More.
    4. Uncheck the box next to ICA Only, and click OK. This tells Citrix Gateway to start using Universal licenses and enables the SmartAccess and SmartControl features.
  4. Enable Trust XML on the Citrix Virtual Apps and Desktops (CVAD) Site/Farm:
    1. On a CVAD Controller, run PowerShell as Administrator.
    2. Run asnp citrix.* to load the snapins.
    3. Run Set-BrokerSite -TrustRequestsSentToTheXmlServicePort $true to enable Trust XML.
  5. Configure Callback URL in StoreFront:
    1. In StoreFront Console, right-click the Stores node, and click Manage Citrix Gateways.
    2. Edit a Gateway.
    3. On the Authentication Settings page, make sure a Callback URL is configured. The Callback URL must resolve to a Citrix Gateway VIP on the same appliance that authenticated the user. The Callback Gateway’s certificate must match the FQDN entered here. If you are configuring Single FQDN for internal and external, then the Callback FQDN must be different than the Single FQDN.

Once the prerequisites are in place, do the following as detailed below:

Endpoint Analysis

Endpoint Analysis (EPA) scans are completely optional. You can configure SmartControl and SmartAccess without implementing any Endpoint Analysis.

Endpoint Analysis is supported on Windows and Mac devices. Other devices, like iOS and Android, do not support Endpoint Analysis. If you want to allow mobile device connectivity, then make sure you have an access mechanism (e.g. ICA Proxy) that works if the Endpoint Analysis scan fails.

Citrix ADC 12.1 and newer support two methods of doing EPA: nFactor EPA, or Classic EPA. Classic EPA will no longer be supported in ADC 13.1 and newer so you should eventually switch to nFactor EPA.

Workspace app on Windows supports EPA when configured using nFactor EPA. Workspace app does not support Classic EPA.

nFactor EPA

EPA can be one of the factors of an nFactor flow. EPA can be performed before authentication, or after authentication.

EPA doesn’t work on iOS/Android. To skip those platforms, see CTX572334 Eliminate Advanced Endpoint Analysis scans on Mobile devices/iOS.

  1. Create an nFactor EPA Action.
    1. The easiest way to find EPA is to use the Search box on the top of the left menu. Or, navigate to Security > AAA > Policies > Authentication > Advanced Policies > EPA.
    2. The EPA Editor link on the right-side of the Expression box lets you configure EPA Expressions. See OPSWAT EPA Expressions below for more details on how to configure an Opswat expression.
    3. For SmartAccess based on the results of the EPA scan, configure the Default Group field with a new group name (doesn’t exist in Active Directory). You’ll later use the Group name in a Session Policy and use the Session Policy name in your Citrix Policy Access Filters or Delivery Group Access Control. Default Group probably only works if the EPA Factor is performed after authentication.
  2. After creating an EPA Action, create an Advanced Authentication Policy of type EPA and select the EPA Action you created earlier.
    1. The expression is either true, or an expression that defines who needs EPA scanning. If you are configuring post-authentication EPA, then you can use group membership (e.g. AAA.User.Is_Member_Of()) expressions.

  3. Create a Policy Label for the EPA Factor. Login Schema should be LSCHEMA_INT.

    1. Bind the EPA Policy to your Policy Label.
    2. If you don’t bind any other policies, then if EPA fails, then the user shown the Access Denied page. If you want authentication to continue even with a failed EPA scan, then bind another policy to the Policy Label.
    3. Create an Advanced Authentication Policy named similar to NoAuth and change Action Type to NO_AUTHN. Expression = true. Bind the NoAuth policy to the Policy Label.
    4. The final Policy Label should have an EPA Factor with Goto = NEXT and the second policy as NoAuth.
  4. In earlier factors that authenticate the user, when binding an authentication policy, click in the Select Next Factor field and select your EPA Policy Label.

    • In the earlier authentication factor, edit the Login Schema Profile, click More, and check the box next to Enable Single Sign On Credentials. EPA as later factor overrides the password collected in earlier factors causing Single Sign-on to StoreFront to fail and this checkbox fixes that problem.
  5. Create a Citrix Gateway Session Policy that is applied when the EPA factor succeeds.
    1. Go to Citrix Gateway > Policies > Session.
    2. On the tab named Session Profiles, click Add.
    3. Name it FullAccess or similar and click Create. The Session Profile does not need any settings.
    4. Switch to the tab named Session Policies and click Add.
    5. Select the Profile you just created.
    6. If you are doing Advanced Policies, then the Expression is AAA.USER.IS_MEMBER_OF(“GroupName”) where “GroupName” is the name of the Default Group you specified when you created the EPA Action. Click Create. If you are doing Classic Policies, then the expression is ns_true.
  6. If your session policy is Advanced syntax, then bind the Session Policy to your Gateway vServer.
    1. Go to Citrix Gateway > Virtual Servers and edit an existing vServer.
    2. Scroll all the way down to the Policies section and click the Session Policies line.
    3. Add Binding and select the Session Policy you will use for SmartAccess. Priority doesn’t matter.
  7. For both Advanced Session Policies and Classic Session Policies, create a AAA Group that matches the Default Group you specified in the EPA Action. CTX278960 says this is also required for IS_MEMBER_OF expressions.
  8. If you are doing Classic Session Policies, then create bind the Session Policy to the AAA Group. If you are doing Advanced Session Policies bound directly to the Gateway Virtual Server, then you don’t need to bind anything to the AAA Group.
  9. You can now use the Session Policy in your SmartAccess configuration. See the SmartAccess section below for more details.

Classic EPA Policies

There are two methods of Classic Endpoint Analysis: pre-authentication and post-authentication. For pre-authentication, configure an Endpoint Analysis expression in a Preauthentication Policy. For post-authentication, configure the Endpoint Analysis expression on one or more Session Policies.

  • With a Preauthentication Policy, if the Endpoint Analysis scan fails, then users can’t login.
  • With a Postauthentication Policy, Endpoint Analysis doesn’t run until after the user logs in. Typically, you create multiple Session Policies. One or more Session Policies have Endpoint Analysis expressions. Leave one policy without an Endpoint Analysis expression so there’s a fallback in case the client device doesn’t support Endpoint Analysis (e.g. mobile devices). The name of the Session Policy is then used later in Citrix Policies and Citrix Delivery Groups.
    • Inside the Session Profile is a field for Client Security expression, which supports an EPA expression. This field is for VPN only, and does not affect SmartAccess.

Preauthentication Policies and Profiles are configured at Citrix Gateway > Policies > Preauthentication.

  1. On the right, switch to the Preauthentication Profiles tab, and create a Preauthentication Profile to allow access.

  2. Switch to the Preauthentication Policies tab, and create a Preauthentication Policy with an EPA expression. Select the Request Action that allows access.

  3. The right side of the Expression box has links to create EPA expressions, as detailed below.

Classic Post-authentication Policies and Profiles are configured at Citrix Gateway > Policies > Session.

  1. When creating a Session Policy, the right side of the Expression box has links to create EPA expressions, as detailed below.
  2. Classic Syntax vs Default Syntax – EPA expressions can only be added to Classic Syntax Policies. If you click Switch to Default Syntax, then the OPSWAT EPA Editor disappears. Use nFactor EPA instead.
  3. If you edit a Session Profile, on the Security tab…
  4. Under Advanced Settings, you will see a Client Security Check String box that lets you enter an EPA Expression. This field applies only to VPN and does not affect SmartAccess. Also, this field does not function if your Session Policy is Advanced instead of Classic.

EPA Expressions

Citrix ADC has two Endpoint Analysis engines: the original Client Security engine, and the newer OPSWAT EPA engine.

OPSWAT EPA Expressions

To configure OPSWAT EPA expressions:

  1. When creating an nFactor EPA Action, click the EPA Editor link.

    • When creating a Classic Preauthentication Policy, or Session Policy, click the OPSWAT EPA Editor link.
  2. Use the drop-down menus to select the scan criteria.
  3. You will see some fields with a plus icon that lets you configure more details for the scan.

    • Note: the text in these policy expressions is case sensitive.
  4. Then click Done.

Additional OPSWAT EPA Info

See the following links for more Advanced EPA information:

Original Client Security Expressions

To configure the original Client Security expressions:

  1. When creating a Classic Preauthentication Policy or Classic Session Policy, click the Expression Editor link.
  2. Change the Expression Type to Client Security.
  3. Use the Component drop-down to select a component.
    1. A common configuration is to check for domain membership as detailed at Citrix CTX128040 How to Configure a Registry-Based Scan Expression to Look for Domain Membership.
    2. Citrix CTX128039 How to Configure a Registry-Based EPA Scan Expression on NetScaler to Look for the Active Device or Computer Name of an Explicit Workstation

Once the Classic Preauthentication and/or Classic Session Policies are created, bind them to your Citrix Gateway Virtual Server:

  1. Edit a Citrix Gateway Virtual Server.
  2. Scroll down to the Policies section, and click the plus icon.
  3. Select either Preauthentication or Session, and select the policy you already created. Then click Bind.
  4. Session Policies with EPA Expressions are typically higher in the list (lower priority number) than non-EPA Session Policies.

EPA Libraries

In NetScaler 12.0 build 57 and newer, the EPA Libraries are updated out-of-band.

  1. Download the latest EPA libraries.
  2. In the Citrix ADC menu, click the Citrix Gateway node.
  3. On the right, in the left column, click Upgrade EPA Libraries.
  4. Click Choose File
  5. Browse to one of the .tgz library files, and click Open.
  6. Click Upgrade.
  7. Click OK when prompted that EPA Library upgraded successfully.
  8. Click Upgrade EPA Libraries again.
  9. Click Choose File.
  10. Browse to the other .tgz EPA library file, and click Open.
  11. Click Upgrade.
  12. Click OK when prompted that upgraded successfully.
  13. To see the versions, click Upgrade EPA Libraries.

EPA Plug-in

The EPA plug-in is automatically deployed when the user connects to Citrix Gateway – either before the logon page, or after the logon page.

To pre-deploy EPA plug-in, see CTX124649 How to Deploy NetScaler Gateway Plug-in and Endpoint Analysis Installer Packages for Windows by Using Active Directory Group Policy. This article describes how to extract the plug-in .msi file, and deploy using Group Policy.

EPA and Portal Themes

The webpages displayed to the user when downloading the EPA plug-in and running the EPA plug-in can be customized by editing a Portal Theme.

Look in the Advanced Settings column on the right for the three EPA pages. Citrix CTX222812 How to Customize Custom Error Messages for NetScaler Gateway EPA Scans.

EPA Troubleshooting

From Citrix CTX209148 Understanding/Configuring EPA Verbose Logging Feature:

  1. Go to Citrix Gateway > Global Settings.
  2. On the right, click Change Global Settings.
  3. On the Security tab, click Advanced Settings.
  4. Scroll down, check the box next to Enable Client Security Logging, and click OK.
  5. When the scan fails, the user is presented with a Case ID.
  6. You can then grep /var/log/ns.log for the Case ID. Or search your syslog.

For client-side logging, on the client machine, go to HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Secure Access Client.

  • Make a DWORD value named “EnableEPALogging“, and set the value to 1.
  • After attempting the scan again, you’ll find the file %localappdata%\Citrix\AGEE\epaHelper_epa_plugin.txt with details for each scan expression.

NetscalerAssasin EPA OPSWAT Packet flow and Troubleshooting shows a Wireshark trace of an EPA scan.

SmartAccess

Links:

Make sure the prerequisites are completed. This includes:

  • ICA Only unchecked on Citrix Gateway Virtual Server
  • Gateway Universal licenses installed
  • Callback URL configured at StoreFront
  • Trust XML enabled on Delivery Controllers

SmartAccess is configured in two places:

  • Delivery Group > Access Policy page in Web Studio in CVAD 2407 and newer has been redesigned. There are built-in Access Policies that you can edit. And you can add Access Policies. They support both inclusions and exclusions. See Citrix Docs for details.

    • CVAD 2402 and older looks like the screenshot below.
  • Citrix Policy (user settings only) > filters > Access control in Web Studio looks like the screenshot below.

    • Group Policy looks like the screenshot below.

In any case, you enter the name of a matching Gateway Virtual Server, and the name of a matching Session Policy (or Preauthentication Policy).

  • Set AG farm name or Site or Farm name to the name of the Citrix Gateway Virtual Server.
  • Set Access condition or Filter to the name of the Citrix Gateway Session Policy (or Preauthentication Policy).
  • You can use * as a wildcard in either field.
  • The matching Citrix Gateway Session Policy typically has an EPA Factor in an nFactor flow that puts the user in a AAA Group that has a group-specific Session Policy bound to the AAA group. That way the Session Policy only applies to connections that match the EPA Expression.

Icon visibility – Access Control at the Delivery Group controls visibility of icons published from that Delivery Group.

  • Access Control on a Delivery Group is Allow only. Icons are hidden from non-matching connections.
  • You can uncheck Connections through Citrix Gateway to hide the published icons from all Citrix Gateway connections.
  • It’s not possible to hide individual published applications. You can hide all applications from a single Delivery Group, or none of them. If you need more granularity, then you’ll have to split the applications onto different Delivery Groups.
  • App Groups do not have an Access Control option. It’s Delivery Groups only.

Citrix Policy Settings – Access Control filter on a Citrix Policy determines if the Policy settings apply or not.

  • Access Control filter applies to User Settings only. It’s not configurable for Computer Settings.
  • You typically configure the Unfiltered Citrix Policy to block all client device mappings. Then you configure a higher priority Citrix Policy with Access Control filter to re-enable client device mappings for endpoint machines that match the Session Policy and EPA Expression.

When connected to a session, Director shows SmartAccess Filters on the Session Details page. Notice the Farm Name (Gateway Virtual Server name) and Filter Name (Session Policy name)

SmartControl

The SmartControl feature lets you configure some of the SmartAccess functionality directly on the appliance. See Configuring SmartControl at Citrix Docs for detailed instructions.

  • Note: SmartControl requires Citrix ADC Premium Edition. If you don’t have Premium Edition, you can instead configure SmartAccess.
  • SmartControl cannot hide published icons. If you need that functionality, configure SmartAccess, either as a replacement for SmartControl, or as an addition to SmartControl.

To configure SmartControl:

  1. Make sure the Prerequisites are completed. This includes: ICA Only unchecked and Gateway Universal licenses installed. Callback URL and Trust XML are not needed.
  2. If you are using a Preauthentication Policy to run an Endpoint Analysis scan:
    1. Edit the Preauthentication Profile.
    2. Configure the Default EPA Group with a new group name. You’ll use this group name later.
  3. If you are instead using a Session Policy to run the post-authentication Endpoint Analysis scan:
    1. Edit the Session Profile
    2. On the Security tab, use the Smartgroup field to define a new group name for users that pass the scan. You’ll use this group name later.
  4. On the left, expand Citrix Gateway, expand Policies, and click ICA.
  5. On the right, switch to the Access Profiles tab, and click Add.

    1. Configure the restrictions as desired, and click Create.
  6. Switch to the ICA Action tab, and click Add.

    1. Give the ICA Action a name.
    2. Select the ICA Access Profile.
    3. Click Create.
  7. Switch to the ICA Policies tab, and click Add.
  8. In the Create ICA Policy page, do the following:
    1. Give the ICA Policy a name.
    2. Select the previously created ICA Action.
    3. Enter an expression. You can use HTTP.REQ.USER.IS_MEMBER_OF(“MyGroup”).NOT where MyGroup is the name of the SmartGroup you configured in the session profile or preauth scan.
  9. Click Create when done.
  10. Edit your Gateway Virtual Server.
    1. Scroll down to the Policies section, and click the plus icon.
    2. Change the Choose Type drop-down to ICA, and click Continue.
    3. Select the SmartControl policy you created earlier, and click Bind.

Related Pages

EUC Weekly Digest – August 26, 2017

Last Modified: Nov 7, 2020 @ 6:34 am

Leave a comment

Here are some EUC items I found interesting last week. For more immediate updates, follow me at http://twitter.com/cstalhood.

For a list of updates at carlstalhood.com, see the Detailed Change Log.

 

XenApp/XenDesktop

App Layering (Unidesk)

HDX

WEM/Profile Management

StoreFront

Receiver

NetScaler

NetScaler Gateway

XenMobile

Global Server Load Balancing (GSLB) – Citrix ADC

Last Modified: Mar 30, 2023 @ 10:18 am

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GSLB Planning

GSLB is nothing more than DNS. GSLB receives a DNS query, and then GSLB sends back an IP address, which is exactly how a DNS server works. The user then connects to the returned IP, which doesn’t even need to be on a NetScaler ADC.

GSLB can do some things that DNS servers can’t do:

  • Don’t give out an IP address unless it is UP (monitoring)
    • If the active IP address is down, then give out the passive IP address (active/passive) instead
  • Give out the IP address that is closest to the user (proximity load balancing)
  • Give out different IPs for internal users vs external users (DNS View)

GSLB is only useful if you have a single DNS name that could resolve to two or more IP addresses. If there’s only one IP address, then use normal DNS instead.

Citrix Blog Post Global Server Load Balancing: Part 1 explains how DNS queries work and how GSLB fits in.

Citrix has a good DNS and GSLB Primer.

When configuring GSLB, don’t forget to ask “where is the data?”. See Citrix Blog Post XenDesktop, GSLB & DR – Everything you think you know is probably wrong!

GSLB Configuration Overview

GSLB Configuration can be split between one-time steps for GSLB infrastructure, and repeatable steps for each GSLB-enabled DNS name.

One-time GSLB Infrastructure configuration

  1. Create ADNS listener on each ADC pair – DNS clients send DNS queries to the ADNS listeners. GSLB resolves a DNS query into an IP address, and returns the IP address in the DNS response.
  2. Create GSLB Sites (aka MEP Listener) – GSLB Sites usually correspond to different datacenters. GSLB Sites are also the IP address endpoints for Citrix ADC’s proprietary Metric Exchange Protocol (MEP), which is used by GSLB to transmit proximity, persistence, and monitoring information.
  3. Import Static Proximity Database – Citrix ADC includes a database that can be used to determine the geographical location of an IP address. Or you can subscribe to a geolocation service, and import its database.
  4. Delegate DNS sub-zone to ADC ADNS – in the original DNS zone, create a new sub-zone (e.g. gslb.company.com), and delegate the sub-zone to all ADNS listeners.

Repeatable GSLB Configuration for each DNS name:

  1. Create one or more GSLB Services per DNS name, and per IP address response – each GSLB Service corresponds to a single IP address that can be returned in response to a DNS Query.
    • Optionally, bind a Monitor to each GSLB Service. Monitors determine if the GSLB Service is up or not.
  2. Create a GSLB Virtual Server per DNS name
    • Bind a DNS name to the GSLB Virtual Server.
    • For active/active – bind multiple GSLB Services to the GSLB Virtual Server, configure a load balancing method (e.g. proximity), and configure site persistence.
    • For active/passive – bind the active GSLB Service. Create another GSLB Virtual Server with passive GSLB Service and configure as Backup Virtual Server.
      • Alternatively, NetScaler ADC 13.1 and newer let you bind GSLB Services in priority order. See Citrix Docs for details.
  3. Create CNAME records for each delegated DNS name – in the main DNS zone, create a CNAME that maps the original DNS name to the delegated sub-zone. For example, CNAME citrix.company.com to citrix.gslb.company.com.

You will create separate GSLB Services, separate GSLB Virtual Servers, and separate CNAMEs for each DNS name. If you have a bunch of DNS names that you want to GSLB-enable, then you’ll repeat these steps for each GSLB-enabled DNS name.

Each datacenter has a separate ADNS listener IP address. DNS is delegated to all GSLB ADNS Listener IPs, and any one of them can respond to the DNS query. Thus, all ADC pairs participating in GSLB should have the same Per-DNS name configuration.

One ADC appliance for both public DNS/GSLB and internal DNS/GSLB?

GSLB can be enabled both publically and internally. For public GSLB, configure it on DMZ ADC appliances, and expose the DNS listener to the Internet. For internal GSLB, configure it on separate internal ADC appliances/instances, and create an internal DNS listener.

Each ADC appliance only has one DNS table, so if you try to use the same ADC for both public DNS and internal DNS, then be aware that external users can query for internal GSLB-enabled DNS names.

  • As described by Phil Bossman in the comments, you can use a Responder policy to prevent external users from reading internal DNS names. 
    add policy patset GSLB_INTERNAL
bind policy patset GSLB_INTERNAL internalHostname.gslb.domain.com -index 1
add responder action DNS_Empty_Response respondwith DNS.NEW_RESPONSE
add responder policy GSLB_DNS_Empty_Response "(!(CLIENT.IP.SRC.IN_SUBNET(10.0.0.0/8)||CLIENT.IP.SRC.IN_SUBNET(192.0.0.0/16)||CLIENT.IP.SRC.IN_SUBNET(172.0.0.0/12)) && DNS.REQ.QUESTION.DOMAIN.CONTAINS_ANY(\"GSLB_INTERNAL\"))" DNS_Empty_Response
bind responder global GSLB_DNS_Empty_Response 100 END -type DNS_REQ_DEFAULT

One appliance resolving a single DNS name differently for internal and public

Let’s say you have a single DNS name citrix.company.com. When somebody external resolves the name, it should resolve to a public IP. When somebody internal resolves the name, it should resolve to an internal IP.

For internal GSLB and external GSLB of the same DNS name on the same ADC appliance, you can use DNS Policies and DNS Views to return different IP addresses depending on where users are connecting from. See Citrix CTX130163 How to Configure a GSLB Setup for Internal and External Users Using the Same Host Name.

If the Internet circuit in the remote datacenter goes down, then this should affect public DNS, since you don’t want to give out a public IP that isn’t reachable. But do you also want an Internet outage to affect internal DNS? Probably not. In that case, you would need different GSLB monitoring configurations for internal DNS and external DNS. However, if you have only a single GSLB Virtual Server with DNS Views, then you can’t configure different monitoring configurations for each DNS View.

To work around this limitation, create two separate GSLB Virtual Servers with different monitoring configurations. Internal DNS uses a CNAME record to reach the GSLB Virtual Server configured for internal monitoring:

  • External citrix.company.com:
    • Configure ADC GSLB for citrix.company.com.
    • On public DNS, delegate citrix.company.com to the ADC DMZ ADNS services.
  • Internal citrix.company.com:
    • Configure ADC GSLB for citrixinternal.company.com or something like that.
    • On internal DNS, create CNAME for citrix.company.com to citrixinternal.company.com
    • On internal DNS, delegate citrixinternal.company.com to ADC internal ADNS services.

Remote Internet Monitoring

For public DNS/GSLB, you don’t want to give out a remote public IP address if that remote public IP address is not reachable. That means the local ADC will need to somehow determine if the remote datacenter has Internet connectivity or not. Here are some methods of verifying the remote Internet connection:

  • Route GSLB Metric Exchange Protocol (MEP) across the Internet. If MEP goes down, then all IP addresses associated with the remote GSLB Site are assumed to be down, and thus the local ADC will stop giving out those remote IP addresses.
  • Bind explicit monitors to each GSLB Service, and ensure the monitoring is routed across the Internet.

GSLB IP Addresses

GSLB is separate from data traffic. The GSLB IP addresses are separate from the IP addresses needed for data.

Some GSLB-specific IP Addresses are needed on each ADC pair:

  • ADNS Listener IP: An ADC IP that listens for DNS queries.
    • The ADNS listener IP is typically an existing SNIP on the appliance.
    • For external DNS, create a public IP for the ADNS Listener IP, and open UDP 53 and TCP 53, so Internet-based DNS servers can access it.
    • A single ADC appliance can have multiple ADNS listeners – typically one ADNS listener for public, and another ADNS listener for internal.
  • GSLB Site IP / MEP listener IP: An ADC IP that will be used for ADC-to-ADC GSLB communication. This communication is called MEP or Metric Exchange Protocol. MEP transmits the following between GSLB-enabled ADC pairs: load balancing metrics, proximity, persistence, and monitoring.
    • GSLB Sites – On ADC, you create GSLB Sites. GSLB Sites are the endpoints for the MEP communication. Each ADC pair is configured with the MEP endpoints for the local appliance pair, and all remote appliance pairs.
    • TCP Ports – MEP uses port TCP 3009 or TCP 3011 between the ADC pairs. TCP 3009 is encrypted.
    • The ADNS IP address can be used as the MEP endpoint IP.
    • MEP endpoint can be any IP – The MEP endpoint IP address can be any IP address and does not need to be a SNIP or ADNS.
    • One MEP IP per appliance – there can only be one MEP endpoint IP address on each ADC pair.
    • Route MEP across Internet? – If you route MEP across the Internet, and if the MEP connection is interrupted, then Internet at one of the locations is probably not working. This is an easy way to determine if remote Internet is up or not. If you don’t route MEP across the Internet, then you’ll need to configure every remote-site GSLB Service with a monitor to ensure that the remote Internet is up.
      • Public IPs for MEP Enpoints – if you route MEP across the Internet, then you’ll need public IPs for each publically-accessible MEP endpoint IP address.
      • Public Port for MEP: Open port TCP 3009 between the MEP Public IPs. Make sure only the MEP IPs can access this port on the other ADC . Do not allow any other device on the Internet to access this port. Port 3009 is encrypted.
    • GSLB Sync Ports: To use GSLB Configuration Sync, open ports TCP 22 and TCP 3008 (secure) from the NSIP (management IP) to the remote public MEP IP. The GSLB Sync command runs a script in BSD shell and thus NSIP is always the Source IP.
  • Public IP Summary: In summary, for public GSLB, if MEP and ADNS are listening on the same IP, then you need one new public IP that is NAT’d to the DMZ IP that is used for ADNS and MEP (GSLB Site IP).
    • Each datacenter has a separate public IP.
    • DNS is delegated to all public ADNS IP listeners.

GSLB Wizard

NetScaler 12 and Citrix ADC 12.1 and newer have a GSLB Wizard at Traffic Management > GSLB.

However, the wizard doesn’t really save any time or steps, so it won’t be documented here.

ADNS Listener

  1. At System > Network > IPs, identify a Citrix ADC-owned IP that you will use as the ADNS listener. This is typically a SNIP.
  2. Create a public IP for the ADNS Service IP and configure firewall rules. UDP 53 and TCP 53 need to be opened from the Internet to the public IP that NATs to the ADNS Listener IP address.
  3. On the left, expand Traffic Management > Load Balancing, and click Services.
  4. On the right, click Add.

    1. In the Basic Settings section, do the following:
      1. Name the service ADNS or similar.
      2. In the IP Address field, enter an appliance SNIP.
      3. In the Protocol drop-down, select ADNS.
    2. Click OK.
    3. No other configuration is needed so scroll down and click Done to close the Load Balancing Service properties.
  5. Highlight the ADNS service you just added and then click Add to create another Service while copying some of the settings from the previously created Service.

    1. Change the Service Name to ADNS_TCP or similar.
    2. Change the Protocol drop-down to ADNS_TCP.
    3. Click OK to close the Basic Settings section.
    4. No other configuration is needed so scroll down and click Done to close the Load Balancing Service properties.
  6. You should have two ADNS services on the same IP address: one for ADNS, and one for ADNS_TCP.
  7. On the left of the console in the menu, expand System, expand Network, and then click IPs.
  8. On the right, you’ll see the SNIP is now marked as the ADNS svc IP.
  9. Repeat the ADNS configuration on the other appliance pair in the other datacenter. Except the other appliance will use its own SNIP as the ADNS Service listener IP address.
  10. Your ADC appliances are now DNS servers.

DNS Security

  1. Citrix ADC includes DNS Security Options, at Security > DNS Security, which can protect your ADNS service.
  2. To protect ADNS, set the Profile to All DNS Endpoints.

Metric Exchange Protocol

This section details MEP configuration between two GSLB Sites. See Citrix Docs for larger Parent-Child Topology Deployment Using the MEP Protocol.

GSLB Sites

  1. The local GSLB Site IP can be any IP, including the same SNIP that you used for ADNS.
  2. Open the firewall rules for Metric Exchange Protocol. The GSLB Site IP on this appliance pair uses TCP 3009 to communicate with the GSLB Site IP on the other appliance pair.
  3. On the left, expand Traffic Management, right-click GSLB, and enable the feature.
  4. Expand GSLB, and click Sites.
  5. On the right, click Add.
  6. In the Create GSLB Site page, do the following:
    1. We’re adding the local site first. Enter a descriptive name for the local site.
    2. In the Site Type drop-down, select LOCAL.
    3. In the Site IP Address field, enter an IP that this appliance will listen for MEP traffic. This is typically a SNIP and can the same as your ADNS IP.
    4. For Internet-routed GSLB MEP, in the Public IP Address field, enter the public IP that is NAT’d to the GSLB Site IP.
    5. For internal GSLB MEP, there is no need to enter anything in the Public IP field.
  7. Scroll down, and click Create, to close the Create GSLB Site page.

  8. Go back to System > Network > IPs, and notice that the IP is now marked as a GSLB site IP.
  9. If you want to use the GSLB Sync Config feature, then you’ll need to edit the GSLB site IP, and enable Management Access.

    1. Scroll down, and enable Management Access. SSH is all you need.
  10. Go to the other appliance pair, and also create the Local GSLB site using its GSLB site IP, and its public IP that is NAT’d to the GSLB site IP.

    1. In System > Network > IPs on the remote appliance, there should now be a GSLB site IP. If GSLB Sync is desired, enable management access on that IP and ensure SSH is enabled.
  11. Now on each appliance, add another GSLB Site, which will be the Remote GSLB site.
  12. In the Create GSLB Site page, do the following:
    1. Enter a descriptive name for the remote site.
    2. Select REMOTE as the Type.
    3. Enter the other appliance’s actual GSLB Site IP as configured on the appliance. This IP does not need to be reachable.
    4. In the Public IP Address field, enter the public IP that is NAT’d to the GSLB Site IP on the other appliance. For MEP, TCP 3009 must be open from the local GSLB Site IP, to the remote public Site IP. For GSLB sync, TCP 22, and TCP 3008, must be open from the local NSIP, to the remote public Site IP.
  13. Click Create.
  14. Repeat on the other appliance.

RPC

MEP defaults to unencrypted on TCP 3011. To fix that:

  1. On the left, expand System, expand Network, and click RPC.
  2. On the right, right-click the new RPC address (the other site’s GSLB Site IP), and click Edit.
  3. On the bottom, check the box next to Secure. In ADC 13.0 64.x and 12.1 build 61.x onwards, Secure is enabled by default. (source = Citrix CTX292743 Configuration Sync, Propagation and MEP Propagation Might Fail After Upgrade to 13.0 64.x\12.1 61.x)

    • If your local GSLB Site IP is not a SNIP, then you’ll need to change the RPC Node to use the local GSLB Site IP as the source IP. In the Source IP Address field, enter the local GSLB Site IP.
  4. Click OK when done.
  5. Do the same thing on the other appliance.
  6. If you go back to GSLB > Sites, you should see it as active.

See Citrix Tech Zone Troubleshooting Citrix GSLB MEP Cheat Sheet

If your MEP connection between GSLB Sites flaps, it might be useful to introduce a delay before remote GSLB Services are marked as Down.

  1. You can do this at Traffic Management > GSLB > Dashboard.
  2. On the right, click Change GSLB settings.
  3. In the GSLB Service State Delay Time (secs) field, enter a delay before the GSLB Services are marked as down when MEP goes down.

    set gslb parameter -GSLBSvcStateDelayTime 15

Static Proximity Geo Location Database

If you want to use DNS Policies, or Static Proximity GSLB Load Balancing, or Responders based on user’s location, import a geo location database.

Citrix ADC has a built-in database at /var/netscaler/inbuilt_db/ that you can use. Or you can download a database. Common free databases are:

For IP2Location, see the blog post Add IP2Location Database as NetScaler’s Location File for instructions on how to import.

CTX235799 NetScaler data formats for Location Database Import

Citrix Github has a Citrix-ADC-GSLB-GeoIP-Conversion-Tool that can convert Maxmind GeoIP City database to Citrix ADC (NetScaler) format.

Import the Built-in Geo database:

  1. In the Citrix ADC GUI, on the left, expand Traffic Management, expand GSLB, expand Database and Entries, and click Static Databases.
  2. On the right, click Add.
  3. Change the Import From selection to File.
  4. Click Choose File.
  5. Browse to /var/netscaler/inbuilt_db/. To browse to the directory, select var, and then click Open.
  6. Repeat for each directory until you reach /var/netscaler/inbuilt_db.
  7. In ADC 12.1, you can select the file named Citrix_Netscaler_InBuild_GeoIP_DB_IPv4. In NetScaler 12.0, select the only file shown. Then click Open.
  8. In the Location Format field, if using the built-in database, select netscaler, and click Create.
  9. After you later create a GSLB Service, when you open the GSLB Service, the public IP will be translated to a location based on the contents of the static proximity database.

Private IP Blocks

Geo Location databases only contain entries for Public IPs. For Private IPs, do the following:

  1. On the left, expand Traffic Management, expand GSLB, expand Database and Entries, and click Custom Entries.
  2. On the right, click Add.
  3. Enter a range of IP addresses for a particular location.
  4. Enter a Location Name in Geo Location format, which is typically six location words separated by periods. You can look in the static proximity database for examples.
  5. Make sure you enter coordinates. Google can find you coordinates for cities.
  6. Click Create.
  7. Continue creating Custom Entries for other private IP blocks.

Use Geo Locations

You can use the Geo locations in a DNS Policy, static proximity GSLB Load Balancing, Responders, and Rewrites:

Prior to Citrix ADC 12.1 build 50, the only option in policy expressions is to match a known location.

Citrix ADC 12.1 build 50 and newer lets you extract the user’s location and use it in policy expressions.

GSLB Services

GSLB Services represent the IP addresses that are returned in DNS Responses. The IP addresses represented by GSLB Services do not need to be hosted on a Citrix ADC, but Citrix ADC-owned IP addresses (e.g. load balancing VIPs) have additional GSLB Site Persistence options (e.g. cookie-based persistence).

  • Each potential IP address in a DNS response is a separate GSLB Service.
  • GSLB Services are associated with GSLB Sites.
  • GSLB Service configuration is identical for active/active and active/passive. GSLB Virtual Server configuration defines active/active or active/passive, not GSLB Services.

GSLB should be configured identically on all Citrix ADC pairs that are responding to DNS queries. Since you have no control over which Citrix ADC will receive the DNS query, you must ensure that both Citrix ADC pairs are giving out the same DNS responses.

To create a GSLB Service:

  1. On the left, expand Traffic Management > GSLB, and click Services.
  2. On the right, click Add.
  3. The service name should be similar to the DNS name that you are trying to GSLB. Include the site name in the service name.
  4. Select one of the GSLB Sites. The IP address you’re configuring in this GSLB Service should be geographically located in the selected GSLB Site.
  5. On the bottom part, if the IP address is owned by this Citrix ADC, then select Virtual Servers, and select a Virtual Server that is already defined on this appliance. It should automatically fill in the other fields. This option is only available when creating a GSLB Service in the Local GSLB Site.

    1. If the IP address is not owned by this Citrix ADC, then change the selection to New Server, and enter the remote IP address in the Server IP field.
    2. The Server IP field is the IP address that Citrix ADC will monitor for reachability.
    3. If the remote IP is owned by a different Citrix ADC that is reachable by MEP, then enter the actual VIP configured on that remote Citrix ADC. The Server IP does not need to match what is returned to the DNS Query.
  6. In the Public IP field, enter the IP address that will be returned to the DNS Query. If you leave Public IP blank, then Citrix ADC will copy the Server IP to the Public IP field. For Public GSLB, the Public IP field is usually a Public IP address. For internal GSLB, the Public IP field is usually an internal IP, and probably matches the Server IP.
  7. Scroll up, and make sure the Service Type is SSL. It’s annoying that Citrix ADC doesn’t set this drop-down correctly.
  8. Scroll down, and click OK, to close the Basic Settings section.
  9. GSLB Service Monitoring – on the right, in the Advanced Settings column, you can click Monitors to bind a monitor to this GSLB Service. Review the following notes before you bind a monitor.

    • Local Citrix ADC VIP – If the GSLB Service IP is a VIP on the local appliance, then GSLB will simply use the state of the local traffic Virtual Server (Load Balancing, Content Switching, or Gateway). There’s no need to bind a monitor to the GSLB Service.
    • Remote Citrix ADC VIP – If the GSLB Service IP is a VIP on a remote appliance, then GSLB will use MEP to ask the other appliance for the state of the remote traffic Virtual Server. In both cases. There’s no need to bind a monitor to the GSLB Service.
    • GSLB Monitor overrides other Monitoring methods – If you bind a monitor to the GSLB Service, then MEP and local Virtual Server state are ignored (overridden).
    • Here are some reasons for binding a monitor to the GSLB Service:
      • IP is not on a Citrix ADC– If the GSLB Service IP is not hosted on a Citrix ADC, then only a monitor can determine if the Service IP is up or not.
      • Monitor remote Internet – For Public DNS, if MEP is not routed through the Internet, then you need some method of determining if the remote Internet circuit is up or not. In that case, you’ll need to bind monitors directly to the GSLB Service. The route of the Monitor should go across the Internet. Or you can ping the Internet router in the remote datacenter to make sure it’s reachable.
      • Traffic Domains – If the GSLB Service IP is in a non-default Traffic Domain, then you will need to attach a monitor, since GSLB cannot determine the state of Virtual Servers in non-default Traffic Domains.
      • TCP monitor – for TCP services (not UDP), a simple TCP monitor is probably all you need. The TCP monitor tries to connect to the GSLB Service Public IP address using the SNIP of the local appliance. Make sure firewall on both sides allows this connection.
  10. Active/Active Site Persistence – If you intend to do GSLB active/active, and if you need site persistence, then on the right you can add Site Persistence and enable Connection Proxy or HTTP Redirect. See Citrix Blog Post Troubleshooting GSLB Persistence with Fiddler for more details. This only works with GSLB Service IPs that match Virtual Server VIPs on Citrix ADC appliances reachable through MEP.

  11. Scroll down, and click Done, to finish creating the GSLB Service.
  12. Create additional GSLB Services for each IP address that will be returned to a DNS query. There should be at least two for each DNS name.
  13. When creating a GSLB Service, select the correct Site, and make sure Service Type = SSL.
  14. The State will probably be down until the other ADC is configured.

Manually Synchronize GSLB Configuration

Copy the GSLB Service Configuration to the remote Citrix ADC pair. You can either repeat the GUI steps listed above. Or you can do the following:

  1. On the left, expand Traffic Management, expand GSLB, and click Dashboard.
  2. On the right, click View GSLB Configuration.
  3. This shows you all of the CLI commands for GSLB. Look for add gslb service commands. You can copy them, and run them (SSH) on other Citrix ADC pairs that are participating in GSLB.

GSLB Virtual Server

GSLB Virtual Server is the entity that links a DNS name with GSLB Services.

For Active/Passive GSLB in NetScaler ADC 13.1 or newer, GSLB Services can be bound in priority order. GSLB will give out the IP address of the lowest order GSLB Service. If that GSLB Service is down, then GSLB will give out the IP address of the next order GSLB Service.

  1. Create a GSLB Virtual Server.
  2. Bind the active GSLB Service but set the Order to 1.
  3. Bind the passive GSLB Service but set the Order to 2.
  4. Bind a DNS name to the GSLB Virtual Server.
  5. Repeat the GSLB Virtual Server configuration on other Citrix ADC pairs participating in GSLB.
  6. Delegate the DNS name to Citrix ADC ADNS.

For Active/Passive GSLB, the Active GSLB Virtual Server will give out a single IP address if that IP address up. If the GSLB Service is down, then it will fail over to a Backup GSLB Virtual Server that gives out a different IP address.

  1. Create a GSLB Virtual Server for the Passive IP address.
    1. Bind the Passive GSLB Service to the Passive GSLB Virtual Server.
  2. Create another GSLB Virtual Server for the Active IP address.
    1. Bind the Active GSLB Service to the Active GSLB Virtual Server.
    2. Configure Backup Virtual Server pointing to the Passive GSLB Virtual Server.
    3. Bind a DNS name to the Active GSLB Virtual Server.
  3. Repeat the GSLB Virtual Server configuration on other Citrix ADC pairs participating in GSLB.
  4. Delegate the DNS name to Citrix ADC ADNS.

For Active/Active GSLB, a single GSLB Virtual Server gives out multiple IP addresses based on load balancing method and site persistence.

  1. Create one GSLB Virtual Server.
    1. Bind two or more GSLB Services to the Virtual Server.
    2. Configure the GSLB Virtual Server Load Balancing Method – e.g., Proximity
    3. Configure Site Persistence:
      1. Source IP persistence is configured on the GSLB Virtual Server.
      2. Cookie Persistence is configured on the GSLB Services.
    4. Bind a DNS name to the GSLB Virtual Server.
  2. Repeat the GSLB Virtual Server configuration on other Citrix ADC pairs participating in GSLB.
  3. Delegate the DNS name to Citrix ADC ADNS.

Configure Active/Passive GSLB in NetScaler ADC 13.1 and newer

  1. On the left, expand Traffic Management, expand GSLB, and click Virtual Servers.
  2. On the right, click Add.
  3. In the Basic Settings section, do the following:
    1. Give the GSLB Virtual Server a descriptive name.
    2. Set the Service Type to SSL to match the GSLB Sevices you intend to bind.

      add gslb vserver <gslb_vserver_name> SSL
  4. Click OK to close the Basic Settings section.
  5. On the left, click where it says No GSLB Virtual Server to GSLB Service Binding.

    1. Click where it says Click to select.
    2. Check the box next to the active GSLB Service and click Select.
    3. In the Order box, enter 1. Click Bind.
  6. To add another GSLB Service Binding, on the left, click where it says 1 GSLB Virtual Server to GSLB Service Binding.

    1. Click Add Binding.
    2. Click where it says Click to select.
    3. Check the box next to a passive GSLB Service and then click Select at the top of the page.
    4. In the Order box, enter 2 so that this GSLB Service is only used if all Order 1 GSLB Services are down. Click Bind.
  7. Click OK to close the GSLB Services and GSLB Service Group Binding section.
  8. On the left, click where it says No GSLB Virtual Server Domain Binding.

    1. Enter the FQDN that this GSLB Virtual Server will resolve.
    2. Click Bind.
    3. If you are doing CNAME (e.g., citrix.corp.com CNAME to citrix.gslb.corp.com, then add domain bindings for both the main FQDN and the CNAME FQDN. Click Close when done.
  9. Click OK to close the GSLB Virtual Server Domain Binding section.
  10. Click OK to close the ADNS Service section.
  11. With GSLB Services assigned to different Order numbers, it is not necessary to configure Backup Virtual Server.
  12. If you bound multiple GSLB Services to a single Order number, then you might want to adjust Method and Persistence.
  13. Click Done to finish creating the GSLB Virtual Server.
  14. On the left, if you expand Traffic Management > DNS, expand Records, and click Address Records…
  15. You’ll see a new DNS record for the GSLB domain you just configured. Notice it is marked as GSLB DOMAIN, and has a default TTL of 5 seconds. You can also see which GSLB Virtual Server it is bound to.
  16. Configure an identical GSLB Virtual Server on the other NetScaler ADC appliance pair. Both NetScaler ADC pairs must be configured identically. You can use Traffic Management > GSLB > Dashboard > View GSLB Configuration to copy the add/set/bind gslb vserver commands from this appliance to other NetScaler ADC appliances.


Configure Active/Passive GSLB in NetScaler ADC 13.0 and older

Passive Virtual Server

  1. On the left, expand Traffic Management, expand GSLB, and click Virtual Servers.
  2. On the right, click Add.
  3. In the Basic Settings section, do the following:
    1. Give the Passive GSLB Virtual Server a descriptive name.
    2. Set the Service Type to SSL to match the GSLB Services that you will bind to this Virtual Server.
  4. Click OK to close the Basic Settings section.
  5. On the left, click where it says No GSLB Virtual Server to GSLB Service Binding.

    1. Click where it says Click to select.
    2. Check the box next to an existing Passive GSLB Service, and then click the blue Select button at the top of the screen.
    3. Click Bind.
  6. Click OK to close the GSLB Virtual Server GSLB Service Binding section.
  7. Click OK to close the GSLB Virtual Server Domain Binding section. The DNS name is bound to the Active Virtual Server, not the Passive Virtual Sever.
  8. Click OK to close the ADNS Service section.
  9. Click Done to finish creating the Passive GSLB Virtual Server.

Active Virtual Server

  1. On the left, expand Traffic Management, expand GSLB, and click Virtual Servers.
  2. On the right, click Add.
  3. In the Basic Settings section, do the following:
    1. Give the Active GSLB Virtual Server a descriptive name.
    2. Set the Service Type to SSL to match the GSLB Services that you will bind to this Virtual Server.
  4. Click OK to close the Basic Settings section.
  5. On the left, click where it says No GSLB Virtual Server to GSLB Service Binding.

    1. Click where it says Click to select.
    2. Check the box next to an existing Active GSLB Service, and click Select.
    3. Click Bind.
  6. Click OK to close the GSLB Virtual Server GSLB Service Binding section.
  7. On the left, click where it says No GSLB Virtual Server Domain Binding.
  8. In the Domain Binding page, do the following:
    1. Enter the FQDN that GSLB will resolve.
    2. Click Bind.
  9. Click OK to close the GSLB Virtual Server Domain Binding section.
  10. Click OK to close the ADNS Service section.
  11. On the right, in the Advanced Settings section, click Backup Virtual Server to add it to the left.
  12. On the left, in the Backup Virtual Server section, select the Passive GSLB Virtual Server, and click OK.
  13. Click Done when done creating the Active GSLB Virtual Server.
  14. On the left, if you expand Traffic Management > DNS, expand Records, and click Address Records…
  15. On the right, you’ll see a new DNS record for the GSLB domain you just configured. Notice the Type is GSLB DOMAIN, and has a default TTL of 5 seconds. You can also see which GSLB Virtual Server it is bound to.
  16. Configure identical GSLB Virtual Servers on the other Citrix ADC appliance pair. Both Citrix ADC pairs must be configured identically. You can use Traffic Management > GSLB > Dashboard > View GSLB Configuration to copy the add/set/bind gslb vserver commands from this appliance to other Citrix ADC appliances.

Configure Active/Active GSLB

  1. On the left, expand Traffic Management, expand GSLB, and click Virtual Servers.
  2. On the right, click Add.
  3. In the Basic Settings section, do the following:
    1. Give the GSLB Virtual Server a descriptive name.
    2. Set the Service Type to SSL to match the GSLB Sevices you intend to bind.
    3. You can optionally check the box for Send all “active” service IPs in response (MIR). By default, GSLB only gives out one IP address per DNS query. This checkbox always returns all IPs, but the IPs are ordered based on the GSLB Load Balancing Method and/or GSLB Persistence.
    4. A new DNS feature called ECS will contain the actual DNS client IP. This dramatically improves the accuracy of determining a user’s location. Without this setting, GSLB can only see the IP address of the user’s configured DNS server instead of the real client IP. Check the box next to Respond with ECS option to enable ECS for site persistence.

      set gslb vserver <gslb_vserver> -ECS ENABLED
  4. Click OK to close the Basic Settings section.
  5. On the left, click where it says No GSLB Virtual Server to GSLB Service Binding.

    1. Click where it says Click to select.
    2. Check the boxes next to multiple existing GSLB Services, and click Select.
    3. Click Bind.
  6. Click OK to close the GSLB Virtual Server GSLB Service Binding section.
  7. On the left, click where it says No GSLB Virtual Server Domain Binding.

    1. Enter the FQDN that this GSLB Virtual Server will resolve.
    2. Click Bind.
  8. Click OK to close the GSLB Virtual Server Domain Binding section.
  9. Click OK to close the ADNS Service section.
  10. On the left, in the Method section, click the pencil icon.

    1. For poximity load balancing, change the Choose Method drop-down to RTT with STATICPROXIMITY as backup.
      1. RTT = Round Trip Time. Each ADC appliance sends a ping to the user’s DNS server. Whichever ADC appliance gets the fastest response determines the site of the GSLB Service. RTT requires that ADC be able to ping anything on the Internet so adjust firewall rules accordingly.
      2. STATICPROXIMITY requires that the Geo Location database has already been installed on the appliance.
    2. Click OK to close the Method section.
  11. On the right, in the Advanced Settings column, click Persistence to add it to the left.

    1. On the left, at the bottom of the page in the Persistence section, change the Persistence drop-down to Source IP.
    2. Enter a Persistence Id.
      1. The Persistence ID signifies the persistence table that each ADC pair shares across the MEP connection.
      2. Each active/active GSLB Virtual Server should have a different Persistence ID (different persistence table).
      3. When you configure the same GSLB Virtual Server on each Citrix ADC pair, specify the same Persistence ID so every Citrix ADC has the same persistence information for this particular GSLB Virtual Server.
    3. In the Time-out field, enter the Persistence Time-out. This is typically the same or longer than the webpage timeout.
    4. Click OK to close the Persistence section.
  12. Click Done to finish creating the GSLB Virtual Server.
  13. On the left, if you expand Traffic Management > DNS, expand Records, and click Address Records…
  14. You’ll see a new DNS record for the GSLB domain you just configured. Notice it is marked as GSLB DOMAIN, and has a default TTL of 5 seconds. You can also see which GSLB Virtual Server it is bound to.
  15. Configure an identical GSLB Virtual Server on the other Citrix ADC appliance pair. Both Citrix ADC pairs must be configured identically. You can use Traffic Management > GSLB > Dashboard > View GSLB Configuration to copy the add/set/bind gslb vserver commands from this appliance to other Citrix ADC appliances.


GSLB Configuration Synchronization Script

Manual GSLB Synchronization

  1. The synchronization script requires SSH to be enabled on your GSLB Site IPs.

  2. Ports TCP 3008, TCP 3010, and TCP 22 must be opened from the local NSIP to the remote GSLB Site IP. The source IP is NSIP, not SNIP.
  3. To manually run the script that syncs GSLB configuration from one GSLB Site to another, on the left, expand Traffic Management, expand GSLB, and click Dashboard.
  4. On the right, click the button labelled Auto Synchronization GSLB.
  5. Use the check boxes on the top, if desired. It’s usually a good idea to Preview the changes before applying them.
  6. Then click Run to begin synchronization.
  7. Click Close.
  8. You can Run it again without previewing it. It seems to take several seconds to complete.

Automatic GSLB Synchronization

  1. There is an automatic GSLB Configuration Sync feature, which automatically syncs the GSLB config every 15 seconds. To enable it on the master appliance, go to Traffic Management > GSLB > Dashboard. On the right, click Change GSLB settings.
  2. Check the box next to Automatic Config Sync. Only enable this on the one appliance where you are configuring GSLB, and want that GSLB config synced to other appliance.
  3. The automatic sync log can be found at /var/netscaler/gslb/periodic_sync.log.

Some notes regarding GSLB Sync:

  • When syncing GSLB Services, it tries to create Load Balancing Server objects on the remote appliance. If the GSLB Service IP matches an existing Load Balancing Server object, then the GSLB sync will fail. Check the Sync logs for details. You’ll have to delete the conflicting Load Balancing Server object before GSLB Sync works correctly.
  • GSLB Sync runs as a script on the BSD shell and thus always uses the NSIP as the source IP.
  • GSLB Sync connects to the remote GSLB Site IP on TCP 3008 (if RPC is Secure) and TCP 22.

Test GSLB

  1. You can test GSLB DNS name resolution from the GUI by going to Traffic Management > GSLB > Dashboard, and on the right, click the button labelled Test GSLB.

  2. Select a GSLB Domain Name.
  3. Select an ADNS Service IP to test it from, and click Test.
  4. The test performs a dig against the ADNS IP. Verify that the response contains the IP address you expected.
  5. Another method of testing GSLB is to simply point nslookup to the ADNS services and submit a DNS query for one of the DNS names bound to a GSLB vServer. Run the query multiple times to make sure you’re getting the response you expect.
    • The syntax is “nslookup <DNS_name> <ADNS_IP>”. The second argument specifies the DNS server that you send the DNS Query to.
  6. The Citrix ADC ADNS services at both GSLB sites should be giving the same response.
  7. To simulate a failure, if the GSLB Service IP is a Citrix ADC Load Balancing, Content Switching, or Citrix Gateway IP, you can disable the Virtual Server.
  8. Then the responses should change. Verify on both ADNS services.
  9. Re-enable the Virtual Server, and the responses should return to normal.

DNS Delegation

If you are enabling GSLB for the domain gateway.corp.com, you’ll need to create a delegation at the server that is hosting the corp.com DNS zone. For public GSLB, you need to edit the public DNS zone for corp.com.

DNS Delegation instructions will vary depending on what product is hosting the public DNS zone. This section details Microsoft DNS, but it should be similar in BIND or web-based DNS products.

There are two ways to delegate GSLB-enabled DNS names to Citrix ADC ADNS:

  • Delegate the individual record –  For example, delegate gateway.corp.com.
  • Delegate an entire subzone – For example, delegate the subzone gslb.corp.com. Then create a CNAME record in the parent DNS zone for gateway.corp.com that is aliased to gateway.gslb.corp.com. For additional delegations, simply create more CNAME records.
    • The incoming DNS query to the ADNS listener is for gateway.gslb.corp.com and not gateway.corp.com. You’ll need to bind gateway.gslb.corp.com to your GSLB Virtual Server. You can bind multiple FQDNs to a single GSLB Virtual Server.

A delegation consists of the following DNS records:

  • A records (host records) that resolve to each Citrix ADC ADNS IP address. If you have two ADC pairs participating in GSLB, then you’ll need one A record for each ADC pair.
    • The A record names are typically something like ns1.corp.com and ns2.corp.com, just like you would name any other DNS server.
    • You only create the A records once. The A records for ADNS services can be used by multiple delegations.
    • These A records for ADNS are sometimes called glue records.
  • NS records for each delegation. The NS records point to the A records that resolve to the ADC ADNS IP addresses. If you have two ADC ADNS IP addresses, then you need two NS records for each delegation.
    • When delegating individual records, you create separate NS records for each delegation. If you have two ADNS listeners, then you need two NS records for each delegation.
    • When delegating a subzone, you only need NS records for the subzone. To GSLB-enable a DNS name, you create a CNAME that aliases to a record under the subzone.

Delegate an individual DNS record

  1. Run DNS Manager.
  2. First, create Host Records pointing to the ADNS services running on the Citrix ADC pairs in each data center. These host records for ADNS are used for all GSLB delegations no matter how many GSLB delegations you need to create. These are sometimes called glue records.
  3. The first Host record is gslb1, (or similar) and should point to the ADNS service (Public IP) on one of the Citrix ADC appliances.
  4. The second Host record is gslb2, and should point to the ADNS Service (public IP) on the other Citrix ADC appliance.
  5. If you currently have a host record for the service that you are delegating to GSLB (e.g. gateway.corp.com), delete it.
  6. Right-click the parent DNS zone, and click New Delegation.
  7. In the Welcome to the New Delegation Wizard page, click Next.
  8. In the Delegated Domain Name page, enter the left part of the DNS record that you are delegating (e.g. gateway for gateway.corp.com). Click Next.
  9. In the Name Servers page, click Add.
  10. This is where you specify gslb1.corp.com and gslb2.corp.com as delegated name servers. Enter gslb1.corp.com, and click Resolve. Then click OK. If you see a message about the server not being authoritative for the zone, ignore the message. Note: you only add one name server at a time.
  11. Then click Add to add the other GSLB ADNS server.
  12. Once both ADNS servers are added to the list, click Next.
  13. In the Completing the New Delegation Wizard page, click Finish.
  14. The delegation is shown in the DNS Manager console.
  15. For proper delegation, the Name Server records should also be added to Citrix ADC. (source = Citrix CTX241493 Citrix Response on DNS Flag Day)
    1. On the GSLB Citrix ADC appliances, expand Traffic Management, expand DNS, expand Records, and click Name Server Records.
    2. On the right, click Add.
    3. In the Domain Name field, enter the name of the delegated DNS name (e.g. gateway.corp.com).
    4. In the Name Server field, leave it set to –<< New >>–, and enter one of the FQDNs for your GSLB ADNS services. This is one of the glue records you created earlier.
    5. Click Create.
    6. Add another Name Server Record for the same domain name. But this time, enter the second GSLB ADNS FQDN. Repeat this process until all GSLB ADNS FQDNs are specified.

  16. Also add an SOA record for the delegation. If you are delegating individual records, then you will need an SOA for each record. If you are delegating a subzone, you only need an SOA record for the subzone.
    1. On the left, in the menu, go to Traffic Management > DNS > Records > SOA Records.
    2. On the right, click Add.
    3. In the Domain Name field, enter the FQDN that you delegated to NetScaler. This can be an individual record, or a sub-zone.
    4. In the Origin Server field, leave it set to –<< New >> — and then enter the FQDN that resolves to one of your ADNS listeners. It doesn’t matter which one you enter.
    5. In the Contact field, enter an email address that is publicly viewable. Replace the @ symbol with a period.
    6. Click Create.
    7. Repeat this on the other ADCs that are participating in GSLB for this delegated DNS name.
  17. If you run nslookup against your Microsoft DNS server, it will respond with Non-authoritative answer. That’s because it got the response from Citrix ADC, and not from the original DNS server that you send the request to.

Delegate a Sub-zone

  1. Run DNS Manager.
  2. First, create Host Records pointing to the ADNS services running on the Citrix ADC pairs in each data center. These are sometimes called glue records.

    1. The first Host record is gslb1 (or similar), and should point to the ADNS service (Public IP) on one of the Citrix ADC appliances.
    2. The second Host record is gslb2, and should point to the ADNS Service (public IP) on the other Citrix ADC appliance.
  3. Right-click the parent DNS zone, and click New Delegation.
  4. In the Welcome to the New Delegation Wizard page, click Next.
  5. In the Delegated Domain Name page, enter the left part of the DNS sub-zone that you are delegating (e.g. gslb for gslb.corp.com). Click Next.
  6. In the Name Servers page, click Add.
  7. This is where you specify gslb1.corp.com and gslb2.corp.com. Enter gslb1.corp.com, and click Resolve. Then click OK. If you see a message about the server not being authoritative for the zone, ignore the message. Note: you only add one name server at a time.
  8. Then click Add to add the other GSLB ADNS server.
  9. Once both ADNS servers are added to the list, click Next.
  10. In the Completing the New Delegation Wizard page, click Finish.
  11. The sub-zone delegation is shown in the DNS Manager console.
  12. For proper delegation, the Name Server records should also be added to Citrix ADC. (source = Citrix CTX241493 Citrix Response on DNS Flag Day)
    1. On the GSLB Citrix ADC appliances, expand Traffic Management, expand DNS, expand Records, and click Name Server Records.
    2. On the right, click Add.
    3. In the Domain Name field, enter the name of the delegated sub-domain (e.g. gslb.corp.com).
    4. In the Name Server field, leave it set to –<< New >>–, and enter one of the FQDNs for your GSLB ADNS services. This is one of the glue records you created earlier.
    5. Click Create.
    6. Add another Name Server Record for the same domain name. But this time, enter the second GSLB ADNS FQDN.

    7. Repeat this process until all GSLB ADNS FQDNs are specified.
  13. Also add an SOA record for the delegation. If you are delegating individual records, then you will need an SOA for each record. If you are delegating a subzone, you only need an SOA record for the subzone.
    1. On the left, in the menu, go to Traffic Management > DNS > Records > SOA Records.
    2. On the right, click Add.
    3. In the Domain Name field, enter the FQDN that you delegated to NetScaler. This can be an individual record, or a sub-zone.
    4. In the Origin Server field, leave it set to –<< New >> — and then enter the FQDN that resolves to one of your ADNS listeners. It doesn’t matter which one you enter.
    5. In the Contact field, enter an email address that is publicly viewable. Replace the @ symbol with a period.
    6. Click Create.
    7. Repeat this on the other ADCs that are participating in GSLB for this delegated DNS name.

Each GSLB-enabled DNS name must be CNAME’d to GSLB:

  1. In Citrix ADC, go to Traffic Management > GSLB > Virtual Servers, and edit your GSLB Virtual Server.
  2. On the left, click in the GSLB Virtual Server Domain Binding section.
  3. Click Add Binding.
  4. Add a domain binding for the CNAME’d DNS name. For example, if the original DNS name is gateway.corp.com, then enter gateway.gslb.corp.com. gslb.corp.com matches the sub-zone that you delegated to Citrix ADC. Click OK.
  5. Repeat the Domain Binding on the other Citrix ADC appliances.
  6. In DNS Manager, if you currently have a host record for the service that you are delegating to GSLB (gateway.corp.com), delete it.
  7. Right-click the DNS zone, and click New Alias (CNAME).
  8. In the Alias name field, enter the left part of the original DNS name. For gateway.corp.com, enter gateway.
  9. In the Fully qualified domain name (FQDN) for target host field, enter the CNAME’d DNS name that is delegated to Citrix ADC. For example, if you delegated gslb.corp.com to Citrix ADC, then enter gateway.gslb.corp.com. The GSLB Virtual Server must be configured to match this longer DNS name.
  10. Click OK.
  11. If you run nslookup for the delegated DNS name, it will first CNAME to the longer name, and then respond with the IP address returned by Citrix ADC GSLB.
  12. You can repeat these steps to delegate (CNAME) additional DNS names to Citrix ADC GSLB.