I've got an odd issue on our XenApp 6.5 farm running Windows 2008 R2.
Randomly the servers, under Network and Sharing Center, will stop recognizing they are in the domain. XenApp still works fine, so does network authentication but our firewall rules are not being properly applied.
It happens randomly on all of our servers and a reboot resolves the issue.
I've added screen shots from two different servers, both on the same farm and domain.