DHCP Issue

Hello,

We have three scopes set up, subnet 1, 2, & 3, on a single DHCP

server. We have a VLAN for each subnet. However, if a machine moves

from an office on subnet 1, to the conference room on subnet 2, the

machine holds the old subnet 1 address. It will not give up the

address on reboot, disable/reenable the NIC, release/renew, anything.

The only way to get the address to be given up and get an address on

the new subnet it to manually go to the DHCP server, delete the lease,

set a static address on the NIC on the machine and ping, then set the

NIC back to DHCP. At this point it will get the correct address on

Subnet 2. Then this must be repeated when they go from the conference

room back to their office on Subnet 1.

This happens whenever a machine changes subnets. All three subnets

are configured as superscopes on a single DHCP server. I was told we

used superscopes because we have a single DHCP server on Subnet 1 that

hands out all addresses.

Anyone have any idea why this is occurring? I feel that it may have

to do with the fact that these are superscopes, thus the pool in each

scope being able to get handed an address from the pool across

multiple subnets. But since I am battling with another person on this

I was hoping for some feedback.

Thanks.

Kevin