that cisco totally hoovers. it's old too, discontinued i believe.

if you're stuck with it - update the firmware and see if you can run dd-wrt,open-wrt or tomato on it. We never tried, just threw them all out.

Read this: http://www.codinghorror.com/blog/201...-a-router.html

Cable modems don't typically act as a dhcp server for a private network. They do have a dhcp server but it's only used when not connected to the cable network. It's there so a pc can connect to the modem and diagnose connection issues. If you have a static IP from comcast, whatever you plug into the cable modem should get that static IP - either a router or a PC. If you plug a PC into the modem and get a 10.x.x.x address, that would be weird.

At least I've never seen that. I suppose someone might make a cable modem combined with a router but I haven't seen one (haven't looked either).

Typically, the router plugs into the cable modem and gets a public IP on it's "WAN" or "Internet" port from the cable modem. Make sure you've got the cable modem <-> router cable plugged into the proper port. You then configure the router to provide a private address range (via NAT - network address translation) via DHCP (typically 192.168.x.x or 10.x.x.x, sometimes 172.16.(<32).x). You should be able to choose the private range.