No access through port after moving server

[PolarCow]

Hi!

I've moved my IIS-server to another part of the network, and then I can't access it no longer.
I used to write

http://computername:port/,

but now I'm getting "The page cannot be displayed".
There are activity on the server, I can see the page there, no change has been done on the server.

The server has been moved behind another switch, could this be the reason? I don't know if the switch has been programmed before (I don't know how you do this/how it has been done).

Please help...