I've been having this problem at work with IP conflicts on two servers.

Both servers are Windows Server 2003 Small Business on Dell dual 2.4 xeons processors.

I walked into work one day to find that 12 people couldn't access the one server. So I went downstairs and it wouldn't let me log on due to the IP Conflict. So I unplugged the network cable restarted the computer changed the IP and plugged the cable back in. Right after that I did a portscan of the entire network, and found one IP on there with the same IP as the server. The scanning program showed it as a cisco product. However the only cisco product we have is a Catalyst 2950 24 port switch.

Just today they called me up again cause they couldn't access the other server. I walked in to find the same exact problem. Except this time, the scanner found no other computers on the network with that same IP.

Theses problems are about 3 weeks apart. All IP's are statically assigned except for about 3 of them.

I can't figure this out.