This one takes the cake.
Couple days ago, a PC tech called into the control center, with an IP conflict problem.
I opened the DHCP control program, got the name of the machine from him, it matched. The lease was fine, not due to run out for some time. When he rebooted, the lease renewed. IP address was in the middle of the list, not a normal candidate for a static IP.
Finally, I went to the desk myself, and copied down the MAC of the conflicting machine. Then we set him up for a reserved IP with a static address, and rebooted the machine. He logged in fine. This, of course, reset the IP in the system registry, and I had him remove the static, and reboot again. After he logged in this time, I removed the reservation, and hadhim renew the address with WINIPCFG. It updated the lease, and I knew he was fine.
Then, figuring I had a rogue static IP on my hands, I tracked it down by pinging and using nbtstat to check the machine name, and then got the current logged on users name from server manager.
Went to the machine and checked it out. It had a lease that began a couple of weeks in the future, and ended the end of next month!
I renewed the lease on that machine, and the problems went away. On checking the past history of the machine in our help desk records, it turns out he had a registry error on startup, a short time ago. The user told me he had been getting ‘weird messages about IPs’ since the error. Apparently, the registry crash caused the IP to be set into the future, with the result that DHCP manager did not see the IP as leased, while the machine would not give it up, as the lease had not expired.
Ever hear of anything like it?
