Both are the same /16 subnet. Windows DHCP Server doesn't seem to let me do this? The reason for wanting to do so is that I want to give one set of clients, let's say 10.10.20.x, different options via ...
Because it's not a Windows DDNS box you'll need to have your DHCP server act as a proxy. If you go to the properties of the DHCP server itself (in the DHCP MMC), select the "DNS" tab and check "Enable ...