Is it possible for a specific interface to only allow access to specific dhcp pools? This is assuming a cisco router(IOS) with dhcp server capabilities.
E.g. For some router, hosts on fa0/0 can obtain an address from pool1 (192.168.0.0/29) via dhcp, hosts on interface fa0/1 can obtain an address from pool2 (172.16.0.0/29) via dhcp.