I have a wireless router (D-Link DI-524) and a cable modem (Motorola SURFboard 3100) which I cannot get to talk to each other. The modem works beautifully when connected to the computer via my Ethernet device (as it is right now), and the wireless router is also performing as expected on its own. When I try to connect the two, it appears that they don't want to communicate.
When I turn on the router, it appears to be exchanging some sort of data with the modem (flashing WAN light) for a few seconds, and then the light abruptly goes dead and stays that way. From the HTML configuration interface for the router, it looks like it can't find a DHCP server on the WAN connection.
The configuration page on the modem reports that everything is okay. It lists my Ethernet device's MAC ID as a known address, but nothing else. It reports that the onboard DHCP server is enabled.
All IP addresses are dynamic; the modem gets one from my ISP, the router is *supposed* to get one from the modem, and computers on the network get theirs from the router.
The most common answer I've seen to this sort of problem is that the modem has become somewhat fixated on the Ethernet device's MAC ID and needs some time to learn that of the router. I've tried all the sane permutations of the solutions I've found and given it plenty of time, but so far nothing seems to help. It sure looks like it's that sort of problem, though.
Is there anything else that might make this work, or am I just missing something obvious?