How to Configure Citrix Load-Balanced Applications Using NAM
Many Citrix-published applications run across a load-balanced farm of Citrix servers. This article describes how to configure the Citrix NAM to support this environment and allow a single WorkPlace link to launch a single load-balanced Citrix app. This could be a published application or a published desktop.
Note: This is supported only with appliance version 8.7.
In the Citrix Presentation Server console, generate ICA files for the application and desktop. The ICA files should include one or more HttpBrowserAddresses, pointing at Citrix XML servers in the farm. If the ICA files do not specify a HttpBrowserAddress, you will not get farm load-balancing.
Create a host resource. This can be ANY random host; WorkPlace will use this host for ACL checking, and will not attempt to communicate with this host.
Create a Citrix Graphical Terminal shortcut for this host resource and upload the corresponding ICA file.
Note: Step 2 and its consequences are very important - once your ICA file specifies a HttpBrowserAddress, the host resource against which the WorkPlace shortcut is created becomes largely irrelevant - it only determines the visibility of the link in WorkPlace.
How this works is:
WorkPlace checks whether the user has access to the host resource you defined in step 2. If yes, the NAM link is displayed.
When the user clicks the link, WorkPlace checks for HTTP browsers in the ICA file. When it finds an HTTP browser, WorkPlace picks one and checks whether the user has access to that host. If yes, WorkPlace queries the HTTP browser as to where the application is available. The HTTP browser responds with the address of a Citrix server (call it "citrix").
WorkPlace sends down a modified ICA file to the client, instructing it to connect directly to this Citrix server ("citrix").
Access control should work normally, based on the resources defined in Step 2. You will also have to define all the Citrix servers in the farm as host resources and give access to these servers as well.