Power surge - insane network problem now

[sjetexas]

Setup :
Cable modem, two computers that are not networked due to a down router, both XP.

Power surge the other night, definitely killed my network router (along with some TVs and a garage door opener).

Problem :
I currently can only get internet if the cable modem is hooked into the integrated network port on one of my computers (call it Computer A). If I plug it into Computer B's integrated network port, I get the error "network cable unplugged". I know what you're thinking....fried network card. But I added a PCI network card and it still won't come up. Ok, bad motherboard on Computer B. But, if I take that network PCI card and plug it into Computer A, it won't work on Computer A (although the integrated network port on Comp A works fine). Ok, bad network PCI card. Bought a new one, different brand....same thing. Called cable modem company, they reset the modem on their end and I power cycled it on mine. Same thing. Changed all the network patch cables, no help. I am not even getting any link lights connecting the cable modem to these network ports except for the integrated port on Computer A.

So the cable modem only works on *one* port on *one* computer. I've tried every kind of combo I can think of and it won't work. The network card installs fine in XP. I've tested the PCI slots with firewire cards and they seem to be okay. What on earth can be wrong?

 

[mechBgon]

Your cable modem knows each NIC by its MAC address. It has one IP address it can give out, and it's currently reserved for one of your two NICs. If you go to the working computer, open a command-prompt window, type ipconfig /release, then it should give up the IP address and now your other computer could probably get the IP address assigned to it by the modem upon a reboot or an ipconfig /renew_all.

Big picture: you should get a new router

Big picture #2: without your router to provide a perimeter firewall, you had better have your software firewalls up and your systems patched.

 

[sjetexas]

Thanks for the replay.
I tried that. I can release the IP, but cannot renew on any other network port. Says it cannot do so with the media disconnected. I can renew on the original working port fine. This is using the same patch cable on both the working and non-working port, on a brand new PCI network card. The network card, PCI slot, and patch cable are all tested okay.

 

[mechBgon]

Turn the modem off and then on again. On second thought, pull the plug on the modem, wait 15 seconds and plug it in again.

 

[sjetexas]

Originally posted by: mechBgon
Turn the modem off and then on again. On second thought, pull the plug on the modem, wait 15 seconds and plug it in again.

Tried, no dice.

 

[mechBgon]

What happens if you do an ipconfig /release and ipconfig /renew, what address does each of the two get? Hehe, I would've knuckled under and bought a new router by now

 

[sjetexas]

The working computer port grabs an IP from the ISP. Everything else just says it can't due to media disconnected. I would of went and bought a new router, but I ordered one a few days ago before the I realized the extent of my problems that should get here Monday. I may snap and go buy/return one. Need to see if I can get connectivity within the LAN and just determine whether I have the oddest cable modem failure symptoms of all time.

 

[sjetexas]

Its GOTTA be the modem. Had my wife plug her laptop in, which she often does, and it won't come up either. This laptop was not plugged in during the power surge. Freaking weird. I am going to have fun explaining this to the cable modem provider and insist that I need a replacement.

UPDATE :

Bought a new router. With the new network card in Computer B, I can get everything up and seeing each other within the LAN. I cannot get the cable modem to work though. No link light when I connect it from the WAN port on the router (multiple patch cables). Only works if I hook it directly into Computer A. Weird.

 

[mechBgon]

Try this: on the computer that the modem likes, use the ipconfig /all command to get the NIC's physical address (aka its MAC address). Now go into your router's configuration menus and enter that as the MAC address for the router to "spoof" to the cable modem.

Result: the modem sees the MAC address that it knows and :heart:'s and the router just kinda laughs up its sleeve and goes along with it Example image here the motherboard's onboard nForce NIC has a unique MAC address of 00301B3D7E63. No other NIC in the world has that MAC address (or should not, anyway). If I tell the router to spoof this MAC address to the modem, then as far as the modem knows, it's still talking to this exact individual motherboard, not a router or some other motherboard.