LesD wrote: I stand corrected. Please excuse my ignorance, but what difference is there whether the router or server provides the DHCP service?

The DHCP server can, in general, be taken away from an SBS, although it is not advisable. One such discussion of this can be found here:

http://sbs.seandaniel.com/2008/10/do-i-absolutely-have-to-run-dhcp-on-sbs.html

That said, it won't work in this instance. Suppose the router becomes the DHCP server. One of its roles will then be to set the DNS server(s) for all clients. Now, the SBS needs to be the DNS server for its network. Take that role away from any Active Directory server at your peril. So, the router would then need to pass the IP address of the SBS as the DNS server, but this won't work as the SBS will be on a different VLAN, inaccessible from the workgroup. Making the router the DNS server (with external DNS servers as forwarders) will cause significant problems for the AD-based SBS network.

Understood. Thank you for taking the time to explain.

The only current models which can do more than on LAN IP Subnet is the Vigor3300V+ or the forthcoming Vigor 3200.