I'm sure your ISP is only giving you one IP address, so is your roomates router setup to do IP-Masquerading?
Frankly, I have no idea (I'm new to these concepts). I looked on the router, and didn't find an option for it.
What does ifconfig tell you?
eth0 Link encap:Ethernet HWaddr 00:E0:18
inet addr:192.168.2.51 Bcast:255.255.255.255 Mask:255.255.255.0
UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1202518 errors:0 dropped:0 overruns:0 frame:0
TX packets:909910 errors:0 dropped:0 overruns:0 carrier:910443
RX bytes:1487060570 (1418.1 Mb) TX bytes:123000245 (117.3 Mb)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:154994 errors:0 dropped:0 overruns:0 frame:0
TX packets:154994 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:53686749 (51.1 Mb) TX bytes:53686749 (51.1 Mb)
The ISP gives an IP (dynamic, I believe), and the router assigns one to each computer.
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.2.0 * 255.255.255.0 U 0 0 0 eth0
loopback localhost 255.0.0.0 UG 0 0 0 lo
default 192.168.2.1 0.0.0.0 UG 0 0 0 eth0
(last one being the router). Not sure what the first one is.
Is there a default route to the router?
How do I check?
Can you ping the windows computer? or versa-visa?
I can ping him - haven't tried the other way round (he's not in right now).
One funny thing. When we installed the router, we could go to it's page and see both our computers listed as connected. Now, for some reason, it only shows mine (even though I can ping him, and he can surf). In fact, I can even share files with him using Samba.