Sign in with
Sign up | Sign in
Your question

repeated mac address

Last response: in Components
Share
March 10, 2006 7:48:09 PM

Hi:

I bough a bunch of Intel 10/100 pro from ebay and many of them have the smae mac addresses such as "00:a4:c0:91:D 2:9c" or "00:b4:c0:91:D 2:9c" under freebsd 5.x.

how could that happen? have someone done something on those mac addresses?

More about : repeated mac address

March 10, 2006 8:12:19 PM

It may be resetting them to known-to-work-with-freebsd mac addresses. Try w/ a different operating system - they'll probably be different.

They permanently are different, but the OS or software can modify them in the software.
March 10, 2006 8:38:22 PM

Quote:
It may be resetting them to known-to-work-with-freebsd mac addresses. Try w/ a different operating system - they'll probably be different.

They permanently are different, but the OS or software can modify them in the software.


jus tried them under xp, none of them are working. they all have the same address "00:a4:c0:91:D 2:9c" or "00:b4:c0:91:D 2:9c"
Related resources
March 10, 2006 8:54:37 PM

How are you getting the MAC addresses of the cards?
In windows, you can do a ipconfig /all from a command prompt.

They should not be different unless some software is changing it.

I can't even find out the manufacturer of "00:b4:c0" or "00:a4:c0" on the IEEE page.

Was this a really shady deal on ebay??? :p 
March 10, 2006 9:07:26 PM

Quote:
How are you getting the MAC addresses of the cards?
In windows, you can do a ipconfig /all from a command prompt.

They should not be different unless some software is changing it.

I can't even find out the manufacturer of "00:b4:c0" or "00:a4:c0" on the IEEE page.

Was this a really shady deal on ebay??? :p 


yes, i think i was screwed by the deal:

fxp0: warning: unsupported PHY, type = 0, addr = 0

oh well
March 10, 2006 9:24:38 PM

Also, from intel... might be able to help you determine what the MAC should be..

"What do the numbers and letters on the bar code label on Intel adapters mean?
There are various numbers and letters printed on the bar code on Intel adapters. Depending on the model and age, these numbers can appear in different locations. Here is a general guide to the markings.

* 6 digits - 3 digits (e.g. 761767-003) - This is the adapter printed board assembly number. The first six digits (which may include letters) are the number we use to absolutely identify the product. The 3 digits following represent minor revisions that have no effect on functionality and can be ignored.

* 12 characters (e.g. 0007E90018EA) - This is the MAC address, also known as the Ethernet ID. This address is stored on the card. Every network adapter built has a unique MAC address. This number uniquely identifies the adapter on the network.

* 5 digits (e.g. 36013) - This number is a manufacturing code used by Intel for internal tracking purposes.

Note: There are other 6 digit - 3 digit numbers on the adapters at various locations, such as the number on the metal bracket and the MP and PB numbers silk-screened onto the board. These represent individual component part numbers and should be ignored when identifying the adapter. "

http://www.intel.com/support/network/adapter/pro100/sb/...
March 10, 2006 9:38:28 PM

Quote:
You might want to read this...
http://64.62.136.189/freebsd-hackers@freebsd.org/msg173...

Go google! :D 


Thanks. But I hardly see it ould OS related issue. It happens with XP too. plus, the same 82559 chip cards, 10 out of 20 are good.

the issue is whether we can restore the mac addresses that were printed on the cards (the bar code numbers).
March 10, 2006 10:00:14 PM

Quote:
You might want to read this...
http://64.62.136.189/freebsd-hackers@freebsd.org/msg173...

Go google! :D 


Thanks. But I hardly see it ould OS related issue. It happens with XP too. plus, the same 82559 chip cards, 10 out of 20 are good.

the issue is whether we can restore the mac addresses that were printed on the cards (the bar code numbers).

I have seen some reference on the internet to cards that were illegal copies using repeat MAC addresses. I can't remember where though.
March 10, 2006 10:56:55 PM

I'm not sure if you can reset the mac addresses. They're using an eeprom, so its possible, but i doubt its allowed. You might want to try contacting Intel and see if they tell you anything.

MAC's are supposed to be unique. On the other hand, you have the printed MAC addresses on the NIC. But if they're illegal cards, then you might be out of luck... :?
!