Multihomed DSfW server

OES11sp1. Is it supported to have multiple network interfaces in the DSfW server? Specifically, this is a second DSfW server installed into the network. I want to add a second nic on this server and connect it to a DMZ where students are located. They can use this server for dhcp and dns, and I can open the necessary dsfw ports on this server as well. However, the default route for workstations on this subnet goes through a firewall which controls access to the rest of the network. One problem seems that I don't have the necessary DNS entries for the second nic, but it appears that if I give the workstations a static route to the server's primary nic via the secondary nic that they can communicate with it. But in any case, must the workstations also be able to access the other dsfw server(s)?

Thanks,
Mike