look for errors in the Agent monitor in Server.
ping cannot confirm the connectivity, try telnet on the agent-server communication ports.
telnet on the server or client side.
Are you using ePO 4.6 or MA 4.6.
MA 4.6 is already EOL.
Regarding port details please look at #:
I am using MacAfee EPo 4.6.5 and agent 4.6
McAfee agent 4.6 is already EOL. ePO 4.6.x is going EOL this year end.