MAC address not unique on ABIT MB

[koma77]

I recently bought an ABIT Fatal1ty MB and was not able to get an IP address from my ISPs DHCP. The reason was that the MAC address of the onboard NIC was already in use somewhere in my ISPs network, so they could not give me an IP address.
A little more research by the support guy showed that the MAC address had been used in several places and in several countries. And that only in my ISPs network!
I wonder, have anyone else with an ABIT board had this problem?

 

[PsYcHoCoW]

have you tried using a router between the cable modem and your comp? see if it fixes that :shrug:

 

[koma77]

I don't have a cable modem, I have an ethernet connector in the wall of my apartment...
And no, I don't have a router in between. It is directly connected to the switch of my ISP.
A router in between should probably fix it though...
But I'm a bit curious about this: have anyone else encountered duplicate MAC addresses? On ABIT MBs even?

 

[Peter]

So, what IS the MAC address on that mainboard? The typical problem would be that the manufacturer forgot to program it at all. Some boards tend to lose theirs during BIOS updates. In either case, contact the maker's support to get it fixed.

The board is supposed to have a sticker somewhere that tells you the MAC address it /should/ have.

 

[koma77]

The MAC address is 00:50:8D:49:B9:1E. Which seems to me like a perfectly OK MAC...
I have emailed the ABIT support and they forwarded the issue to Taiwan. Weeks ago...

 

[GunmanUK]

Try this:
http://www.nthelp.com/NT6/change_mac_w2k.htm

 

[koma77]

I've tried that, and it works. But it's really just a workaround since the change is not permanent, right?


I recall that the very first time I powered up my MB it said that the CRC of the bios was corrupted and that it would start from a fresh one. Maybe that is the root cause for all this?

 

[GunmanUK]

From the article I posted it would suggest that the change is permanent as part of the change involves a reboot.

 

[koma77]

It is not really permanent: windows just sets the MAC address automatically at each boot. But when I boot into linux or run a live cd, the MAC is the old original one.
I've checked in my (updated) BIOS, and there is nowhere to change the MAC there either. But the MAC address is reported as part of the POST...

 

[Peter]

You're not supposed to change the MAC. It is up to the card or mainboard vendor to assign a unique one. As a user, you don't have access to this uniqueness information, and hence, if you assign a random one, you're going to make it no better, if not worse.

 

[koma77]

I know, but it seems like the vendor ABIT maybe did not do a good job on the uniqueness... And perhaps I can pick a MAC address that will not cause any harm elsewhere.

 

[GunmanUK]

Since when are you not supposed to change the MAC address? They are not written "in stone" for the very reason that the OP has here.
Anyone can change them. Hence the uselessness of MAC filtering on wireless networks
There are even programs that do it for you.
Windows
http://www.neset.com/?cat=projects&subcat=all
Linux
http://www.alobbs.com/modules.php?op=modload&name=macc&file=index

 

[Varun]

I know this doesn't answer your question but I wouldn't have my computer hooked up without a router. I'm sure if someone wanted to hack my system they would but I will at least do the basics to slow them down.

Plus it fixes your MAC problem.

Plus they are cheap

 

[koma77]

I will consider buying a router...

I noticed that there actually is a sticker on my MB with the following on it: 00:50:8D6:69:B7. Since the (erroneous) MAC of my NIC is 00:50:8D:49:B9:1E it seems the one on the sticker is what it should have been.

Maybe the one I have now is a MAC used for factory testing or so... Darn it.