Switch clogged by crashed machine

[specialj]

We have a server room with several computers all attached to one Linksys switch. This weekend, none of the computers could see any part of the network outside the switch (the internet, the gateway, the rest of the LAN). When I power cycled the switch connectivity came back for about five minutes before disappearing. The problem seemed to be a Windows 2000 Pro machine. The machine was locked, and upon restart everything cleared up. The same thing happened again this morning. I know it's not the switch, I've tried a different switch with the same problem, it seems to be this one server. It's fully patched and up to date. Has anyone heard of a problem like this with Windows? Does anyone have any idea what the computer could be doing to clog the switch, preventing even pings to computer it could see five minutes ago?

Any insight would be appreciated.

 

[bcastner]

Check your network for a rogue DHCP server. I was called into a site last week and someone had brought from home a wireless router and connected it in their office.

 

[vipergg]

Also look for viruses , one machine with a virus can even bury a big cisco switch .

 

[Routerman18250]

First two things to look for are viruses and Bad NIC cards.