Apparently 10.64.92.10 is in use on the network (but it really isnt!)

[dsk]

Hello!

So we have this issue where a secondary domain controller W2K3 reported an IP conflict on the network. Seems like something else has its IP address, but we have checked and double checked everything and cant seem to find what (if) anything that has it.

We've recently just moved over to a virtualised environment and it was initially working fine.

For some reason we can ping the IP, but tracert shows up nothing. Tried RDP to the IP and also web access, nothing again. DNS and DHCP also show negative for it.

Bit stuck on what to do.

I have come across this MS KB: Error message when you try to set an IP address on a network adapter but we've done that to no avail

help

[pritchardavid]

Try wiping the whole list of leased addresses, that way whatever this is, it should find a new ip address

[maniac]

Can you do an ARP lookup to get the hardware address, then look up the routing tables on your switch(s) to pin point the offending bit of hardware (assuming you have managed switches of course) that might help you find it. It's likely it will just return the ligitimate servers address, but there's always a chance.

P-dave's suggestion is also a good one, I do this as a matter of course every now and then, particularly when we get a lot of new hardware and chuck a lot of old stuff - it stops old bits of hardware hanging onto reservations and causes no harm.

[GrumbleDook]

I tend to favour making everything a reserved IP and keep a very limited scope where possible. This also allows for a better audit trail when tracking down the exact machine which is causing problems.

[pete]

Is that secondary DC virtual?
Did you give it a static IP before you installed vmware tools / xen tools / whatever PV addons?
Did you then assign that same static IP to the "new" virtual nic created after the tools install?

Normally it bitches if you do this, but handles it fine. You may have found the exception. Try removing the other NIC from device manager.

[jamesfed]

Did you remove the network adapter settings before you virtulised?
You may find that the old hardware still has ahold of your IP adresses (even though its not in use).

[FN-GM]

Can you see what it is in your DNS?

[PiqueABoo]

Can you do an ARP lookup to get the hardware address, then look up the routing tables on your switch(s)

That would work if it pings, otherwise you normally get a Windows event log entry which has the MAC in it (in the log on the system that is complaining about the conflict). I usually look up the vendor the MAC belongs to in the IEEE OUI because that can sometimes help tell you what device wotdunnit.

[dsk]

Cheers guys. After some ARP lookup and looking for the culprit on the core switch, we got it. Still not too sure what the device is, but unplugged the port it was using and managed to get our controller back onto that IP.

I have a feeling it might some new WiFi access points that were installed over the holiday, but cant check.

Cheers again! You guys are awesome!