AirPort: Can Connect to Base Station But Not to Internet When Using PPPoE

Your computer may connect to the base station but not to the Internet or local network when using a PPPoE DSL or cable modem service. Your computer connects to the base station with a strong signal, but it cannot connect to the Internet or your local network. The Network preference pane may show an IP address of 10.64.64.64 for the Built-in Ethernet port. This typically occurs after adding an AirPort Base Station or third-party wireless access point where wired Ethernet was previously used to connect to a PPPoE DSL or cable modem service. In this scenario, the base station should be the only device connecting via PPPoE to the modem. The wireless connection from client to base station is not PPPoE. When you see these symptoms, the client computer is continuing its attempt to connect over the Built-in Ethernet port via PPPoE, despite the fact that no Ethernet cable is connected.