Agent Client running, but still has live status down. Why?

Agent Client running, but still has live status down. Why?

I just started to use Desktop Central to see if I want to work with it.
I installed the server site and have now installed the agent client on two systems. On both systems it is running, but on the server side it says the client is down.

Could some one give me some tips on what I'm doing wrong and what I should do tofix this?

Best regards,
Dennis