Okay, this one is really pissing me off...

I recently added a windows XP machine to my home network. So, there are two XP Professionals, and my debian server.

The XP machines are on the same workgroup, they can access the web, they can both ping and access shares on my linux server.. but, they cannot talk to each other. I don't quite understand.. they can't even ping each other by IP. I've gone so far as to fully update both machines via the Windows update, disable all firewalls and antivirus software... However, both machines STILL can't talk to each other.

They connect to the same gateway- A dlink router with the address 192.168.0.1.
I've even configured both windows machines with static IPs, 192.168.0.102 and 192.168.0.103.

Any ideas???

Perhaps I should explain my network setup. I'm beginning to think that the problem may be with my physical topology. I have a modem, which is connected to my router. The router is also connected to my switch.

All ports in the house are then connected directly into this switch, including the two conflicting machines. However, my server is connected directly to the router. Could there possibly be problems with this setup?

Also, a laptop can communicate with both machines.. which further suggests the problem is related to my topology rather than a single machine.

1. open a cmd prompt and type ipconfig for each windows machine; in debian, open a terminal and type ifconfig eth0
all your addresses must be in the same range, & judging by what you've listed they prolly are.
ensure they all have the same netmask, such as 255.255.255.0 - which is fine for smaller networks.

2. the topology seems fine.
you could eliminate the switch if there are enough ports on the router.

3. on your xp machines, in network properties, tcp/ip properties, go to advanced, wins tab, "enable netbios over tcpip"

4. are there any other computers / printers on the network besides the 2 xp and the 1 debian? if so, do any of them get "duplicate network name" or something like that on the screen?

let us know.

Sorry, but I actually resolved this problem last week. It seemed to be a problem with the switch.. It did not seem to have any uplink/backbone port, and the switch-router cable was simply plugged into one of the switch's regular ports. So, machines on the switch could not talk to each other.