RAS

I have a w2k adv server running RAS. My data provider (nuvox)installed a pretty cool device that servers as a router/firewall/DHCP
server. When my RAS client log into the network, then can access the Microsoft Mail server and all the internal network devices, but they do not get an IP address assigned and can not go to the internet or send internet mail. I configured the RAS server to use NETBUI and TCP/IP. What have I forgotten? Is this possible?