Connected, no internet

I recently got an RBK33 to replace my AirPort Extreme, but during the set up process is it never able to find my internet connection.  My modem is a TP Link TC-7610 connected with Comcast.  I have the Static IP information pulled from the AirPort and attempted to enter that under the "advanced setup" section, again with no success.  The AirPort and my computer have no issues getting an internet connection, so I'm not sure where the problem is.