Tony,

By default, SBC delivers their routers set up with NAT enabled, which may not be what you want. It turns out to be easy to fix, but you can't do it through the administrative web interface on the box. You need to telnet in, and change settings that way. I called SBC, and they transferred me to a support guy from the router hardware vendor, who walked me through it. I'm not sure why they don't document this for business class customers, as it would seem that many of those would rather run in bridging mode.

--Dan.