MAC address
Short for Media Access Control address, a hardware address that uniquely identifies each node of a network. In IEEE 802 networks, the Data Link Control (DLC) layer of the OSI Reference Model is divided into two sublayers: the Logical Link Control (LLC) layer and the Media Access Control (MAC) layer. The MAC layer interfaces directly with the network media. Consequently, each different type of network media requires a different MAC layer.

On networks that do not conform to the IEEE 802 standards but do conform to the OSI Reference Model, the node address is called the Data Link Control (DLC) address.

muhhahaha you thought this was about macs... hahaha... its about media access controls...

The MAC address is what the computer uses to search for other computers on the network.

We use IP computer uses MAC.

I actually have a question based on your fascinating and informative post! Is it possible to use one's broadband cable service on another computer if you rip his/her NIC out and install it into your own? Or is it possible to take the original customer's MAC address and use it for your own through some devious means? To make the situation more clear, the original customer will not be using the cable service, and he/she'll lend the cable modem to another person. Heh this sounds almost like a math problem don't it?

P.S. I doubt it'll work because there's a special signal (internet feed) going through the original customer's cable isn't there? :wink:

In theory it would work because the computer is registered by the NICs hardcoded MAC address to the cable company.

Obviously the other person would have to be using the same cable company.

I don't think there is any way of the cable company knowing the exact location of the registered NIC.

I now believe Adhesive is right and the connection box, is house specific.

the internet connection is usually "house specific" so to speak.
i.e. it would require you being in the same house as the other guy. you could most likely swap to modem though without getting screwed.

I may be wrong but, i believe that the service has to be "turned on" at the post where the cable comes to the house. That is how the cable around here works anyway.

ill say....arent u a tricky one magoo.....

Not here mine is registered by NIC MAC address. If I change NIC I have to re-register it.

you can just plug the cable modem into any copmputer... the modem has its own MAC address like sid said... i hva done this countless times setting up new machines.

mac address's can be changed, quit easily under windows xp/2k

its a known trick, also xp/2k can have multiple ips assigned to the one nic which is another method of annoying the crap outa network admins when they see all their dhcp'd ips disapear to one tard (altho its quit easy to fix, i now laff at those who have the problems)

still the network card and modem both have their own mac address's

Yes both have MAC addresses,But can cable admins get a MAC table from there modems,and can they not check a packet for source and destination addresses.Or check what subnet the MAC is at for swapping MODEMS?

actually most IPOC vendors use the MAC address of the cable modem <which of course we know is not a modem, but an ethernet bridge, since there is no MODulation of the signal from digital to analog, nor dEModulation>

further, that MAC is bound to a particular network segment. Yours.

yes you can-- but you can't plug the modem into just any network segment, on most IPOC vendors. Once it's MAC is registered to a given network segment, it's only usable on that segment unless you call up and have things switched about by changing the account.

We tried borrowing a friend's cable modem to prove that a given line was having prob lems one time and it wouldn't work.

binding multiple IPs to a NIC has been around since at least NT.

IP does NOT equal MAC

Correct MAC is like the VIN #/serial #, every ethernet component has one, and it can be traced to a given manufacturer, product and model #.
almost all components can spoof the MAC of another connected component, many can have any legitimate MAC # programed to it

"The Medium Access Control (MAC) protocol is used to provide the data link layer of the Ethernet LAN system. The MAC protocol encapsulates a SDU (payload data) by adding a 14 byte header (Protocol Control Information (PCI)) before the data and appending a 4-byte (32-bit) Cyclic Redundancy Check (CRC) after the data. The entire frame is preceded by a small idle period (the minimum inter-frame gap, 9.6 microsecond (µS)) and a 8 byte preamble."
A possible problem would be if you assigned a Linksys router MAC to a IBM NIC, and the remote computer attempted to activate some feature the NIC did not support.

An IP is a network routing protocol
"The IP (Internet Protocol) is a protocol which uses datagrams to communicate over a packet-switched network. The IP protocol operates at the network layer protocol of the OSI reference model and is a part of a suite of protocols originally developed by the US Department of Defense (DoD)."


A network devise may have multiple IP's at once, but only 1 MAC.
In the cable modem scenario there is a nother set of numbers that are addressed, which is why your friends modem didn't work for your computer however if you were within the same node he should be able to run his modem and computer on your cable line under his own account. or you could call the cable company and have the modem reassigned to your account, but then it would no longer work for him.

2K and XP <and IIIRC, NT> all disable multiple IP binding once DHCP is actuated on an IP stack. How is it you get them to bind multple IPs?

Don't have a DHCP server here, or I'd give 'er a go...