I'm running into several systems, across various horizon view 5.2 pools that are showing the "status: Agent unreachable Pairing State: Paired and secured." I've attempted several methods to bring them back to an "Available" state with no luck. I've removed the tools and agent in the common process (http://myvirtualcloud.net/?p=952) and re-installed both. The desktops are able to resolve an nslookup of both connection servers as well as access a telnet session to port 4001.
Agent Version: 5.2.0.987719
Tools version: 9.0.12.35149
Hosts: 5.1.0, 2000251
Gobal Setting > Security > Message security mode: = Disabled
Connection server version: 5.2.0-987719
Windows 7 desktops