mac address/cable modem prob

Hi all,
Got me cable modem on Thursday (im in UK by the way), all working fine, setup on my main pc, however I would like to setup a linux firewall, I spent until 3am Friday morning trying to get an ip assigned from my cable provider, set up the linux box to use dhcp, and EVERYTIME the dam thing recieved an IP, but it was always a LOCAL (192.168, or 10.40) IP, I phoned NTL (provider) and they said that once registered, a MAC address was assigned to my NIC, and I can have 5 of these if I want, now does that mean that if I take the NIC out of my main pc, and put it in the linux box it will work as the card will then be recognised? and then I can signup again on my windows system? All I had to do to get connected on windows was type in an ip address they gave me in the address bar and it took me to a sort of signup page, I cant do that through linux (console only- and Im not an expert- someone was helping me setup the linux), has anyone any suggestions/ideas?
Thanks


Next time you wave - use all your fingers

Hi,
Thanks for the reply, I finally got it sorted yesterday with a lot of help from various people. Things work similar here to the way you explained things, except the cablemodem I have is actually built into the digital tv box (i.e. the tv reciever has an rj45 socket on the back), the MAC address in my case was actually the hardware ID of the card, go to start/run put winipcfg , the adapter address shown is the hardware id of the NIC, I put the "registered" nic in the linux box and with a lot of messing finally got it online, I since found out (took 3 calls to tech support as they were clueless) I cant actaully register up to 5 cards, but aparantly only 2 can be online at once, as you said, they must scan and kill connections if too many are active.
Thanks again for the reply.


Next time you wave - use all your fingers