Here's the odd situation:
Have a guest at a hotel I do IT for. He's reporting that he can't get a dhcp address, and when we configure his card with a fixed address it fails to ping itself, though it can ping loopback OK. He says he was using the wired card in his office, yesterday, and he was on wireless down the street at Starbucks earlier today.
Nobody else in the hotel has problems with dhcp, so it's not the switch or other infrastructure.
My guess is his network card has gone south. Any other ideas?