Two Dells, One Modem

uke
I cannot figure this out.
PC: 2 identical Dell Optiplex PCs
Router: Netgear GS105 5-port switch
Modem: Terayon TJ 715
ISP: Comcast High Speed


PC1 has internet. PC1 can send/recieve files from PC2
PC2 has no internet. PC2 can send/recieve files from PC1
If PC1 is reading PC2's files for too long (or executing files like videos) they will stop talking to eachother. PC1 will continue to have internet. Eventually they start talking again (~10-15 min later)

PC1's internet settings are all set to "Obtain automatically"
PC2's settings have to be set manually to match PC1's (except for the I.P., I use the same I.P. as PC1 but +1) in order to talk to PC1.
PC2 will not connect to anything if settings are set to automatic.

I ran Network diagnostic and it failed in Network adapters -> default I.P. gateway, DNSServerSearchOrder.
If I set everything to automatic config it passes but I get the dreaded "Limited Connectivity", no default gateway, no DNS server, and no WINS server

Question:
How should I be setting up the network connection on PC2?

 

The Netgear GS105 appears to be just a switch and not a router. If your modem does not have a router built in, you're going to need a router to NAT your local network behind and route traffic between your local network and the ISP. The router would also act as your gateway and, potentially, DNS.

 

damn, noob mistake.
what the hell is a switch for then?
should I get a router or an extra LAN card with Internet Connection Sharing?
(for WIN XP)

 

In a nutshell, a router allows one network to talk to another. A switch just carries traffic on the local network. You can use switches in conjunction with a router--to allow more computers to connect to your local network. Personally, I'd choose a router over "internet connection sharing" from a single PC. Also, the NAT piece of the router allows the computers on your network to "hide" behind the single IP address provided by your ISP on the internet. Hope that helps.