Okay, you have to look at a file named something like hosts in the directory etc.
/etc/hosts See if it is there. That file then needs to define all of the other systems along with names. So first, you need a "local only" IP address for your network. This should be 192.168.x.y , where x can be any number from 1 to 255, and y should be the computer's individual ID number (1-255). So my network's *MASK* is 255.255.255.0, and my network's address is 192.168.1.0 (the '0' computer address is a broadcast address for the network.) You then need to go around to each computer in the network, and set up a TCP/IP protocol, and assign an IP address with a different unique number 'X' for each. Usually, the server will have x=1, then other computers can have x=2, x=3, etc. As you go, write down each computer in the list, and also assign each computer a name. Names should not be confusable with people's names, nor should they be confusable with project names or even the actual computer's name (no 'IBM' 'DELL3', etc.) One good set of names is trees, for example. "OAK","ELM","WILLOW", etc. Or cars "TEMPO","CIVIC", "F100", etc. So you write all these down on a sheet of paper. You can add any other aliases you want, though. Now edit at that "hosts" file, and add some entries to it. Each line should contain the IP address of the computer, it's name ('Elm'), and then any aliases you want. Now also come up with a name for your network (I have "netname" below, but it could be "trees" instead. I'm not sure, but it could need to be the name of the workgroup.) 127.0.0.1 localhost 192.168.1.1 elm.netname aliaselm 192.168.1.2 oak.netname aliasoak1 aliasoak2 192.168.1.3 birch.netname aliasbirch and so on. Once you have this set up, now you can go ahead and "ping oak.netname" and it should work.