Do MAC addresses change?

[Phoenix]

Okay, now I know this is likely gonna be a stupid question. lol but since I'm relatively new with network's and nic's since a couple of months ago I signed up for cable modem service from my local cable company.

The reason I ask if the MAC adresses change is because RECENTLY I upgraded my video card and decided to watch what irq's went where since I also removed some other add on cards that I no longer needed. Anyways, my nic and my video card are BOTH using the same IRQ 11, which with windows irq steering isn't much of a problem but usualy when I get an instant message from AIM it cause's things to freeze for half a second. I am planning on moving the card to another pci slot so it has its own irq. But I wanted to know if the mac address changes and what not.

-Phoenix-

P.S. No I'm not new to computers, he he. Just never had an opportunity to play with networks.

 

[Russ]

No, the MAC address doesn't change.

Russ, NCNE

 

[lowtech1]

Yes MAC address does change every time you install a new NIC

 

[Wik]

The mac address is part of the NIC, He would only see a different MAC address if he put in a different NIC. Even if you did change cards a different MAC address at the NIC should not matter. The cable modem's MAC address is the one registered at your ISP.

 

[Phoenix]

Okay first things first. Thank Your guys for your replys.

Russ: Figured that was the case that each MAC address was card specific and didn't change when removed and put in another slot.


Lowtech: Yes, with a new NIC I expected the MAC address to change just since this is my first time playing with network stuff I had no clue whether or not a simple slot change could force the card to a new MAC address.

Wik: Your statement makes my line of thinking correct. BUT you say my cable modems MAC address is what my isp locks on to/registered at? Might be true but I doubt it, from what I have heard (not saying its 100% accurate) it seems as though the cable modem stores the NIC's MAC address and uses that as your verifaction to use the service. Plus, I saw the installer make a point of getting my MAC address written down on my forms. But thats neither here nor there, if and when I decide to change the NIC or add a router at a later date I will be sure to make sure the one I choose can SPOOF this cards mac address to save me some trouble.

Once again guys thank you for your help with this information

 

[R0b0tN1k]

You should be able to tell the ISP the MAC addy of the new card and they'll take care of it. Unless they're total bastards.

 

[bigshooter]

If you are using some token ring cards, you can change your mac. Just felt like sharing.

 

[IsOs]

Is there a way to asign a MAC address?

 

[spidey07]

Yes, you can change the MAC address within the NIC driver, but depends on NIC and driver.

Also called LAA (locally administered address) or DLC. Word to the WISE - you will never need to change your MAC address...don't mess with it, some ranges are reserved for broadcast and multicast applications and could cause you NIC to malfunction.

 

[Neoplasia]

Yes I also thought you could change the MAC depending on the driver. Seems to me I remember doing that in college.

 

[bigshooter]

Doesn't it depend on the card more than the driver? The card would have to flash in the new mac or something wouldn't it? You couldn't just write a driver that fooled the card into overriding the hardcoded mac, could you?

 

[WoundedWallet]

I don't know much about changing MAC addresses, but it brings the question of what number could you change it to?

Unless each card had a set of numbers that it could use, I think that a random change would risk having two cards with the same address sometime, somewhere.

It seems wasteful.