I have installed OPS Center 12 on a server and deployed agent successfully on some servers that are located on the same VLAN.
I tried to deploy the agent on a server that is located on a different VLAN but the job failed. The server has Solaris 10 (just like other servers). I can ping the server from OPS Center server normally and I also started SSH and Telnet sessions succesfully. There is no firewall between the two servers.
"As strange as this sounds, I've found that if I choose the option to manage the client without an agent, it works. Then I go into the OS asset in the asset tab, and in the actions menu, there is an option to Switch Management Access. This then goes out and install and successfully configures the agent. I guess somehow setting up the SSH stream of information magically allows it to see the proxy interface it couldn't before."