I had some machines on an XenDesktop 5.6 farm that were not registering. [Reviewing this again, I realize that it was actually ALL of the machines] The first place I went to check was on in the Desktop’s registry to make sure the DDCs were correct: HKLM\Software\Citrix with HKLM\Software\Wow6432Node\Citrix\VirtualDesktopAgent\ListOfDDCs
WOW6432Node since this particular system was a 64 bit Windows 7 box. The registry key had both of the DDCs listed with a space between then. Check. Event Viewer just showed a generic message stating a failure to register with any DDCs.
Looking at my Eventlog on the actual DDC, I came across this message :
The Citrix Broker Service failed to determine the base settings needed for the Virtual Desktop Agent of machine ‘<FDQN>’

The stated resolution is to check generic KB article CTX126990 but the real answer for me was in CTX129644!
I had some weird licensing issue where my license server information was corrupted/blanked out. After following the instructions in CTX129644, all machines began registering fine.



So if you consider yourself the bleeding edge type, you might want to head over to Microsoft today and check out their Office 2013 Preview βeta!

When one thinks of backing up a Netscaler, the first thing that comes to mind is the Netscaler configuration file, ns.conf. There are a number of other files, however, which are also crucial to the operation of your appliance, for example, your license file(s), SSL certificate(s), etc. At the very least, it would be time-consuming to locate, download, install and reconfigure the above in the event of an appliance failure.