dhcp server - one mac on multiple subnets

[Erik Persson <erik-maillist@djingis.se>]

Hello!

We have a dhcp-server (isc dhcpd v 2.0p15) that is responsible for 
multiple subnets. This is the standard debian sarge version of the 
server (not version 3 though).
Between the subnets and the dhcp-server we have a router which is doing 
dhcp-relaying.

I was under the impression that you could have the same mac-adress on 
multiple subnets and that the dhcp server would offer the correct ip 
adress based on which subnet the request originated from.
This doesn't seem to be the case in our setup however.

Is this a setup question or am I wrong?

Sep 24 16:49:56 shere dhcpd: DHCPDISCOVER from 00:0f:ea:b3:ec:cc via 
192.168.11.254
Sep 24 16:49:56 shere dhcpd: DHCPOFFER on 192.168.5.209 to 
00:0f:ea:b3:ec:cc via 192.168.11.254
Sep 24 16:49:56 shere dhcpd: DHCPREQUEST for 192.168.5.209 from 
00:0f:ea:b3:ec:cc via 192.168.11.254
Sep 24 16:49:56 shere dhcpd: DHCPACK on 192.168.5.209 to 
00:0f:ea:b3:ec:cc via 192.168.11.254

Regards,
Erik Persson.