PowerMac G4 Won't Connect to Internet

I have a 400mhz PowerPC G4 connected via ethernet to DSL through the Apple Airport base station. The G4 doesn't have an Airport card and doesn't support Airport Extreme. A wireless MACBOOK also connects to the network perfectly. Until recently, the PowerPC worked fine.

Upon startup Safari prompts a message saying that I wasn't connected to the Internet. I've restarted the modem, base station and router, restarted the machine several times and gone through the Network Diagnostics several times. Still no connection. I have connected the Ethernet cable directly to the modem, and also directly to the base station. Nothing seems to work.

When I open Safari, I get the "You are not connected to the Internet" message and the Network Diagnostics button. Clicking on that, in the left margin there is a Network Status listing showing the Ethernet with a red or green light. This will toggle back and forth between connected and not connected every few seconds. Network Settings is shown with a yellow light. ISP, Internet, and Server all show a red light with a "Failed" message.

Another issue is that on stgartup my clock reads March 24th 2001 if that has any significance. It was on server time before.

Otherwise the computer operates flawlessly.

Thank you.