The Virtual Desktop Agent (VDA) have an option during installation where you have to point out the XenDesktop Controllers by hostname, IP address or just by pointing out the XenDesktop Farm. If you happen to point out the farm it is most likely to not get registered at the XenDesktop Controller in Studio. The solution, apart from reinstall and making another choice, is to manually point the XenDekstop Controllers out. This solution has it’s benefits and can be used in several other situations. For example if you’ve put a couple of hours down to get the Master Image ready and already had MCS create your pool, if you happen to change the hostname or IP address of the XenDesktop Controller(s), etc.
So what you need to do is alter or create the following Registry key:
1. Navigate to HKLM\Software\Citrix\VirtualDesktopAgent
2. Alter/create the key ListOfDDCs (REG_SZ)
3. Type your XenDesktop Controllers hostnames (FQDN) or IP address. If you have several you separate them with one space, i ex “host1.domain.local host2.domain.local”.
Note: If you typed in the hostnames, you also need to do the 4th step, otherwise you’re done:
4. At the same location (HKLM\Software\Citrix\VirtualDesktopAgent) create a key named UseCnameLookup (REG_DWORD) with the value 1. (1 = Enabled, 0 = Disabled)
This can be set via GPO and distributed to the XenDesktop Controllers via Computer Group or by adding the specific computers to that GPO.
If you read the pages in my reference you’ll notice that Citrix has a separate location for the x86 and the x64 platform. I have tried the x64 instructions on a x64 platform, but didn’t get it working, while the x86 instructions (the above) worked for both platforms. This applies to XenDesktop 7.1, so it may have changed for the most recent version 7.5.