Question : Removing a DHCP Lease

I have a network of WindowsXP computers  that was set up as a peer-to-peer network with all systems using static IP addresses.  I added a SBS 3003 R2 server and promoted all the workstations from a workgroup to a domain.  For some reason, one of the clients has been assigned a different IP address by the server.  I see this when I try to ping the client from the server be computer name.  The static address is 10.0.1.107 but the ping shows 10.0.1.175, which is in the pool of addresses available for laptops that are occasionally attached to the network.  All the other clients see the problem client correctly.

The 10.0.1.175 address doesn't show up in the list of reserved address in he DHCP console.

I  tried setting the address of the problem computer as fixed in AD.  It shows up in DHCP as inactive.

The problem computer seems to behave normally in all other respects, getting  it's roaming profile from the server, getting updates, etc.

Answer : Removing a DHCP Lease

1/ Did you tried to run the Reconcile command from the DHCP console? (Reconcile All Scopes...)

> http://www.computerperformance.co.uk/w2k3/services/DHCP_Database_Backup.htm#Reconcile


2/ I'd check that all client computers are configured as follow :
NIC TCP/IP properties > Prefered DNS server > SBS IP (internal IP if 2 NIC's).
You can do that automatically with a GPO.

3/ I'd remove static IP's (on all clients) and create DHCP reservations instead (if that's an obligation, if not just let the DHCP server manage IP's, it has been created to simplify IP management and it works best this way).

4/ If you need to delete a DHCP lease for a specific computer on the LAN, you simply right click the corresponding IP adress in the DHCP console and select "Delete". Reboot the client (or renew) and it should work.