Connecting from another client to server on same network

I have two Macs on the same home network (connected to an Airport Base Station) with OpenFire installed on one of the two machines (MachineA). I can connect to the server from the same machine with a Jabber client (latest version of Adium). When I try to connect to MachineA’s server from MachineB, also via Adium, I am unable to do so.

I tried using both the ip address and host name as the ‘Connect Server’ in jabber client for MachineB, but no luck.

Each machine’s client is connecting with a unique username, which has been created via the OpenFire Admin console.

Is there anything else I need to do for the non-local client to connect to the server on MachineA?