How to create a firewall exception

Our server unit has 2 new Novell servers that were just implemented in our environment.  The problem is I cannot see them or access them, but when i turn off the firewall locally on the machine - i can see the servers.  How do i set up a firewall exception to alllow the access to the Novell servers.  i dont know what questions to ask to get the required info to create the exception.

please help me...

thanks