Having issues getting our Chromebooks to print to our Ricoh network printer. Desktops will print fine through Chrome, it's just an issue with Google Cloud Print saying the printer is offline.

I'm guessing this must be a network/internet issue, we have a Smoothwall web filter which acts as the proxy server.

What I have done:

Updated Chrome on the print server
Installed the Cloud Print service
Updated printer drivers
Restarted server and then tried all of the above again...