DHCP client roaming issues

[Erik]

Hi,

We've setup a new network with three vlans. The first vlan contains
all of our servers, the second and third vlans contain our two
different usergroups.

When user A connects to the second vlan he gets an (correct)
ip-address from our dhcp server in the server vlan. (our routers have
setup ip helper-addresses).
When user B connects to the third vlan he also gets an (correct)
ip-address from our dhcp server in the server vlan.

Now when user A moves his machine (without turning it off, just
disconnecting and reconnecting the cable) from vlan two to vlan three,
he doesn't get a new ip-address and continues to use the old address.
We do not see the machine requesting a new address via the standard
discover-offer-request-ack dhcp sequence.

When user A releases his address prior to moving the machine
everything works fine. Releasing the address once connected to the new
network does NOT resolve the problem.

Any hints on how to solve this?

Regards,

Erik

 

[Phillip Windell]

Turn the machine off when you move it. You aren't supposed to leave it
running and move to a different subnet,...that only works if you stay in the
same subnet,..as you've noticed.