ethtool get permanent MAC address returns all 0's

Question

I need to read permanent (burned-in) MAC address of network adapter. Since MAC address can be easily spoofed, I need to read the real one which is written on EEPROM. I need to do it using C++ on Linux.

I tried using ethtool which is quite good and works fine. However on some systems it does not work as intented.

ethtool -P eth0

returns this:

Permanent address: 00:00:00:00:00:00

and

ethtool -e eth0

returns this:

Cannot get EEPROM data: Operation not supported

Network Adapter has following info:

driver: ucc_geth
version: 1.1
firmware-version: N/A
bus-info: QUICC ENGINE

Linux kernel version is: 2.6.32.13

Question is: Can i fix this issue with any update(driver, kernel etc)?

Additionally, I make the same ethtool calls with ioctl function in C++. Is there any way to fix this inside the code? Or is there any other way to get the permanent MAC address from EEPROM?

score 1 · Accepted Answer · edited Apr 13 '17 at 12:13

1

If you haven't find the answer yet, you might want to check this out.

https://serverfault.com/questions/316976/can-i-get-the-original-mac-address-after-it-has-been-changed

edited Apr 13 '17 at 12:13

Community

1
1

answered Jun 17 '14 at 08:25

goktan

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Ziffusion · Answer 2 · 2013-09-05T08:20:40.523

0

Take a look at a couple of things.

Look at packets on the wire (using a sniffer) emanating from this NIC and see the MAC address being used.
Look at the output of "ifconfig -a eth0". If the MAC address is the same as on the wire, then you can get that MAC address using the mechanism that ifconfig uses.

edited Sep 05 '13 at 08:20

answered Sep 05 '13 at 08:07

Ziffusion

8,779
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So this means packets on the wire have the real (permanent) MAC address even if the real MAC address is modified? – Kerim Oguzcan Yenidunya Sep 05 '13 at 08:32
1

Of course not. That would defeat the purpose of changing the MAC. – MSalters Sep 05 '13 at 10:48

ethtool get permanent MAC address returns all 0's

2 Answers2