I just bought a new Airport Extreme and I am currently running off of Comcast Infinity using the Surfboard SBG6580 modem and router. I want to run the SBG6580 as just the modem and use the Airport Extreme as the router so I get an extended wireless signal. I have tried to set this up myself and can't seem to get the setup going. I've also followed a couple online threads and still nothing. Any help is greatly appreciated.