# Second ethernet card corrupts the first's MAC

## Alabattai

I am experiencing a very weird problem after adding a new ethernet card.

The MAC of my first card, an integrated Realtek 8169, changes. Two last bytes remain as they were, but others are now 00. Additionally, the card fails to operate normally after manualy restoring the MAC with ifconfig. The second card (realtek 8139) appears to be working fine.

The funny thing is, when I boot Windows, everything is fine. Then, after booting gentoo, it still works fine. On the second boot of gentoo, the MAC f**ks up again, thus forcing me to boot windows before every gentoo boot.

My kernel version is gentoo-sources-2.6.32-r2.

Any ideas?

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## nativemad

lol... that is really strange!

What do you have got in /etc/udev/rules.d/70-persistent-net.rules then!?!

Does dmesg tells you anything useful?

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## d2_racing

Run this and reboot :

```

# rm /etc/udev/rules.d/70-persistent-net.rules

```

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## Alabattai

It doesn't change anything. This file contains two entries for my first card: one for the correct MAC, one for the corrupted. (and an entry for the second card of course)

Removing it only causes the system to create an entry with the corrupted MAC and the card still doesn't work. (but the "transmission" light is flashing)

dmesg doesn't show that anything is wrong.

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## krinn

Once the error is there, reboot with a livecd to see if it work.

edit: even me i don't know what i was trying to say.

I just mean, boot gentoo, let the error come, and then instead of booting in windows, boot from a livecd (it's to see if it's a kernel issue: sure it's one, the driver or the kernel, but it might be from a kernel version and livecd might have one earlier than yours OR a bad option in the kernel).Last edited by krinn on Thu Jan 28, 2010 7:24 pm; edited 1 time in total

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## richard.scott

can you show us the contents of /etc/udev/rules.d/70-persistent-net.rules

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## eccerr0r

I'll apologize up front that I don't know what's going on here, but I may have a similar issue here.

I also have an rtl8169 that appears to have its MAC address corrupted once in a while with no real pattern.  It's at least consistently corrupting so my persistent-net-rules will take the same card each time so I don't have an ethX incrementing/shifting problem.  I do have two ethernet ports on this machine - the onboard SiS900 doesn't get used but does get insmodded...

I only detected this when I noticed I had wrote down the MAC address of this card and suddenly noticed another unknown MAC address on my network...same as the one I wrote but first bytes were different... then I checked this machine and sure enough they were the changed bytes... weird.

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## Alabattai

Tried to boot from livecd, but even then the issue remains. Looks like I'll have to stick with two PCI cards.

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## d2_racing

In fact, it's the only way to do it I think.

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