MAC Addresses

[Nathan England]

Our cable modem went out due to lightning this weekend and it was replaced 
today. When the cable guy put a new modem on the computer, it saw it okay. 
Our cable modems have to dialup first, then they get a new ip address and 
then you're on the net. But after he installed the new modem, it dialed up, 
but afterwards the computer could not get an ip address.

The cable guy said it was because their servers had attached the mac address 
to the cable modem. He said the either they had to release it from the 
servers ( and he couldn't get ahold of anyone to do this as the servers are 
in missouri?) or we could physically remove the nic from the comp and boot it 
without the nic. Then shutdown again, replace the nic, and boot up and that 
would fix it because the nic would loose the mac address of the cable modem.

I just nodded my head and agreed. But it didn't work. Luckily I have two nics 
in the machine, eth0 for the cable and eth1 for the internal network. I 
switched them and everything is okay.  But now I have questions.

1) Is there any truth to what he said? Does a nic hold the mac address of a 
modem or something that gives it an ip and only allow two macs in memory? 
(that's what he said, it would only remeber two macs)

2) If that's true, is there a way to release the macs from a nic without 
rebooting or shutdown the machine and removing the card?

Thanks for any insight.
Nathan