Internet Connectivity from RCN MODEM

Hey guys need help!!!! I have a RCN modem giving an

IP: 207.237.244.76 DG:207.237.240.1

I also have a linksys router
WRTU 54g,after I create a W/L profile n connect to it I still cannot go online.The security was WPA security,Power cycled network and yet doesnt go online