Unusual DHCP Leases
Posted on 2003-02-20
I just installed a Windows 2000 Advanced Server to replace a recently retired server. This new server is a replica of the old one...in that it has the same name, IP Address and Domain. I installed the new server on an isolated network with 5 PC's connected to it for testing. When I completed the 'replication' I simply took the old one off the network and put the new one on. Took 2 seconds and no one knew I have even changed the servers.
My question is: I am running DHCP on that server. Which is functioning as expected. All of my users are showing in the Address Leases...IP Address - Name - Lease Expiration - Type Unique ID. The addresses are also reflected in the DNS table...with the corresponding reverse lookup.
However, I have 5 leases showing up every day that only have the IP Address...no name - it does have the Lease Expiration and Type...BUT the Unique Address (MAC) is 30 alpha-numeric characters long. These are not showing up in the DNS table either.
I can not ping those IP's. I have no idea where they come from. As a generic trouble shooting gesture, I have been deleting them as soon as they show up...in the theory, I could trace the problems back to the time when I deleted the leases. This has gone on for 2 weeks now and I have not had any reports of problems after I delete those IP's.