IP address conflicts

[animosis]

For that last few months, I've been experiencing a strange problem on my network. I have been receiving occasional IP conflicts with my local computer and something else on our network. We run DHCP, so I can't understand why I'm getting IP conflics, even after the lease on the IP has run out.

I can obtain the MAC address of that IP, but I don't know how to isolate the piece of hardware (or software) on the network using that address. Can anybody help me out?

 

[trusted]

If it is the same IP address that is in conflict, just set an exclusion for it in DHCP and the conflict will stop happening.

You can run a tracert on the IP address in question and you will recieve the name of the offending hardware in the response.

 

[mrdenny]

If it's the same IP every time, it sounds like someone put a static IP in a device. Doing a traceroute to the machine should help clear up the issue. "nbtstat -a" will give you some info as well (if it's a windows box).

Denny

--Anything is possible. All it takes is a little research. (Me)

 

[Zelandakh]

It is usually a printer. Excluding it will solve the problem but not isolate the trouble.

Give yourself a reservation on another IP in DHCP. Restart. Wait until the offending hardware gets "your" IP. Then IE to it and see if it tells you. If not, try telnet. If not, try something like GFi LANGuard scanner to interogate it.

 

[animosis]

Here's what I think we're going to do.

Individually turn off each of the switches and ping the IP. Once I isolate which part of the network it is coming from, I'll be able to get rid of it. To be honest, I think it's probably a dying print server somewhere.

The traceroute idea won't work because this is a private network. There are no hops for the IP to go through, so it won't tell me anything.