No, it won't take away the routing function. On your Server 2k3 DHCP you will have to have configure the gateway IP (your router's IP). The router is currently handing out IP, DNS, and the gateway. The DNS and Gateway are the same coming from your router... which its pointing to the IP address of the router. When you remove DHCP from the Router, you have to configure DHCP on the server. Within DHCP on the server you'll have to configure the options to hand out DNS and the Gateway. Unless you decide to host DNS on your Server 2k3, the DNS and the Gateway will remain the router's IP. If you want to host your own DNS, the DNS option in DHCP will need to be configured with the Server's IP address.