home network troubles - fixed!!

[lamplighter]

I will attempt to make a diagram of my current home network:

[edit]click here for a much clearer diagram[/edit]
cable modem (1 IP) ---> COMP #1 (XP) ------ NIC #1 , , , | switch ports |
, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |--- NIC #2 ---> 8 ................2...1 <--- COMP #2 (Win2k)
, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ^-----------COMP #3 (Linux)

Alright, that wasn't as clear as I hoped, but anyways, computers #1 and #2 have been doing fine with just those two. But now that I am back for Easter weekend, I turned on Comp #3. Both #2 and #3 worked for a while, it seemed like 20 min, but then neither could get to the web (although both still had their 192 IPs and could ping #1, 192.168.0.1). I have ICS enabled on Comp #1. I am using a 3com 8 port switch, and not using uplink, so I guess having it go to port 8 means nothing. I have to reboot Comp #1 for the others to get on the net.

After searching around for quite a while tonight, I figure my solutions are:
1) fix my current setup, but I have no idea how... it works and then doesn't, and I don't know what I'm looking for (before I had multiple IPs but somehow @home cut one off, so the computers were knocking each other off, but I don't understand why they would knock each other off now, if they are)

2) get a router... could I get suggestions on what a good trade would be? Cause I have this 3com switch, a 4 port hub, and a Duron 600 for trade, so I could either trade for a 4 port router (or 5? I need 4 computers to get on) or just get a 1 port and keep my switch (or hub). There is also a special at Futureshop for a refurbished Netgear 4 port router for $70 CDN (~$45 US) that I could go for.

[edit]
3) use my linux box as a router... however I have very limited nix experience, so I'd definitely need a good tutorial or 2!
[/edit]

Any advice is greatly appreciated! Thanks in advance.

 

[sohcrates]

do #2 and #3 consistently come back online as soon as you reboot #1?

when they "stop working" after 20 minutes, can you ping any addresses outside of your local network? (i.e. you can't go to www.whatever.com but you can ping it's IP) ?

If you can get through with IP alone, then it's probably a DNS issue

Does AIM and what not still work at that point?

 

[lamplighter]

Wow sohcrates I think you are right about it being the DNS. If I leave the Linux computer (#3) out of it, #2 works fine. But when I try to get #3 on the net, neither can get it, but now that you say that, I tried and I can ping yahoo.com's IP but not yahoo.com on both. I didn't really think about that, but that does seem familiar, having to manually set the DNS servers for computers #1 and #2. I will try that now, thanks!

 

[lamplighter]

That was it, I put in the DNS servers for the others and it works fine now. A few months away from my home network and I overlook that, yeesh

Thanks again sohcrates!

 

[sohcrates]

Good guess on my part

Glad it's working