Is it possible to have a DHCP server serve subnets for multiple network segments, but not its own local subnet?
I have a DHCP server on a subnet 10.x.x.x. It serves approximately 125 subnets on various 10.x networks. I'm attempting to migrate this DHCP server to a new server, which resides on a different subnet. I'm doing this with IP helper. The new DHCP server sits on a subnet 10.y.y.y, and I have test servers, which will act as DHCP clients, sitting on the 10.x.x.x that I want to use to test the new DHCP server.
However, so far, I've been unable to configure the server on 10.x.x.x to ignore hosts on its own subnet. If I remove the subnet stanza, I get an error that DHCP is not configured to listen on any interface. If I leave it, both servers attempt to answer the DHCPDISCOVER, and the old one seems to win (presumably because it's "closer").
I want the DHCP server on 10.x.x.x to listen on the local network interface (so it can continue to issue addresses to other networks), but not serve DHCP to the hosts on that network (so only the DHCP server over IP helper offers IP's).
Is there a way to do this?
