eth0 & eth1 have same MAC address

anctop · 12-12-2016, 10:05 PM

Hi,

Recently we acquired a "Gigabyte X99-Ultra Gaming" mainboard.

The O.S. is Slackware64-14.2.

The mainboard has two NICs (Intel and Atheros), but they appear to have the same MAC address.

The BIOS shows only the MAC of the Intel chip, which matches that reported by the O.S.

HDT also detects two ethernet devices, but without MAC info.

The "dmesg" output reads :

Code:

> :
> :
> alx 0000:0b:00.0 eth0: Qualcomm Atheros AR816x/AR817x Ethernet [1c:1b:0d:09:34:d2]
> e1000: Intel(R) PRO/1000 Network Driver - version 7.3.21-k8-NAPI
> e1000: Copyright (c) 1999-2006 Intel Corporation.
> e1000e: Intel(R) PRO/1000 Network Driver - 3.2.6-k
> e1000e: Copyright(c) 1999 - 2015 Intel Corporation.
> e1000e 0000:00:19.0: Interrupt Throttling Rate (ints/sec) set to dynamic conservative mode
> e1000e 0000:00:19.0 0000:00:19.0 (uninitialized): registered PHC clock
> e1000e 0000:00:19.0 eth1: (PCI Express:2.5GT/s:Width x1) 1c:1b:0d:09:34:d2
> e1000e 0000:00:19.0 eth1: Intel(R) PRO/1000 Network Connection
> e1000e 0000:00:19.0 eth1: MAC: 11, PHY: 12, PBA No: FFFFFF-0FF
> :
> :
> alx 0000:0b:00.0 eth0: NIC Up: 1 Gbps Full
> e1000e: eth1 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None
> :
> :

Both interfaces are usable and working as usual, but they're reported to have the same MAC address "1c:1b:0d:09:34:d2".

Is this abnormality harmful ?

c0wb0y · 12-13-2016, 12:20 AM

Don't worry about that. The real gospel is revealed here:

Code:

ip link

anctop · 12-13-2016, 02:30 AM

Quote:

Originally Posted by c0wb0y

Don't worry about that. The real gospel is revealed here:

Code:

ip link

Thank you for your suggestion, but I'm sorry to report that there's no difference.
The output of "ip link" reads :

Code:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 1c:1b:0d:09:34:d2 brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 1c:1b:0d:09:34:d2 brd ff:ff:ff:ff:ff:ff

onebuck · 12-13-2016, 07:52 AM

Hi,

Delete the file; /etc/udev/rules.d/70-persistent-net.rules

Then reboot the system to regenerate that file. After the regeneration, what do you see for the network devices?

Hope this helps.
Have fun & enjoy!

Fat_Elvis · 12-13-2016, 02:23 PM

Eh... just a quick and dirty solution if you need different mac addresses in the least fiddly way: https://github.com/alobbs/macchanger

Not a permanent fix, obviously.

c0wb0y · 12-13-2016, 02:37 PM

I don't think deleting the udev rules would make any difference. Gigabyte is doing some funky stuff at PHY level. So, it's like at chip-level there's an internal arp/rarp table.

tramsch · 12-13-2016, 02:38 PM

Hi anctop,

have you searched the BIOS for strange settings (somewhere deep :-) ) for the NICs?

But you should try the udev reset onebuck suggested first.
Is this a fresh installation?

br
Florian

Fat_Elvis · 12-13-2016, 02:46 PM

Quote:

Originally Posted by c0wb0y

I don't think deleting the udev rules would make any difference. Gigabyte is doing some funky stuff at PHY level. So, it's like at chip-level there's an internal arp/rarp table.

You mean fiddling with the MAC address on one card would affect the both of them?

Not sure how MAC addresses are assigned.

jefro · 12-13-2016, 03:01 PM

"Not sure how MAC addresses are assigned." It used to be that a chip on the board had been burned with the company id and then sequential number and could repeat in use. You could order them by number. After that the chip was programmable but various means. Then you can modify some by software.

Kind of looks like the ports are teamed by intel or the bios. Might be an intel program to check it.

Could be a goofy setup by board maker. Some oddity of uefi setting.

I'd at least boot to some other clean distro to double check.

anctop · 12-13-2016, 05:54 PM

Thank you for all the advices.

I've traversed the whole BIOS menu tree to look for NIC-related stuff. The only finding has already been mentioned in my original post : "The BIOS shows only the MAC of the Intel chip, which matches that reported by the O.S."

Deleting "/etc/udev/rules.d/70-persistent-net.rules" has no effect at all. I do agree with the view that it is likely a hardware/BIOS issue.

Moreover, I notice that the mainboard manual says explicitly "Teaming is not supported". This creates another confusion. If that is the case, then it is natural to expect seeing two distinct MAC addresses rather than a somehow "merged" one.

c0wb0y · 12-13-2016, 06:06 PM

If you lookup the MAC address '1c:1b:0d:09:34:d2', it would show that its Gigabyte's.

It's so no surprise teaming would not work there.

jefro · 12-13-2016, 07:19 PM

" Killer™ E2400 Gaming Network / Intel® Gigabit LAN with cFosSpeed
Killer™ E2400 is a high-performance, adaptive gigabit Ethernet controller that offers better online gaming and media performance compared to standard solutions. Intel® Gigabit LAN networking, a popular choice with gamers, delivers several performance-enhancing features such as advanced interrupt handling to help reduce CPU overhead and Jumbo Frame support for extra large data packets"

Sure looks like intel product along with all the other chips in it. http://www.gigabyte.com/products/pro...px?pid=5809#ov

UEFI can present hardware to the OS as part of the specification. I'd still run some other distro or two on it to see what happens. Try Ubuntu 16 LTS first. It tends to better support uefi.

I get the feeling we did see some problem with this killer nic before on LQ.

Maybe it is the cFosSpeed doing this? Pretty sure slack or linux won't have support directly as far as I know.

Ztcoracat · 12-13-2016, 08:40 PM

Quote:

I get the feeling we did see some problem with this killer nic before on LQ.

Yes I helped with one of them on an Alienware laptop last year.
If my memory serves me correctly the ath10k driver is needed and should be in the newer kernel.

http://askubuntu.com/questions/76982...n-ubuntu-16-04

I agree; Ubuntu and Mint are much more user friendly with the UEFI interface.

anctop · 12-13-2016, 08:48 PM

Just finished booting with Ubuntu-16.04.1-LTS installation media.

In the live system, the two NICs cannot be turned ON simultaneously, only one at a time.

The "dmesg" output reads :

Code:

> :
> :
> alx 0000:0b:00.0 eth0: Qualcomm Atheros AR816x/AR817x Ethernet [1c:1b:0d:09:34:d2]
> alx 0000:0b:00.0 enp11s0: renamed from eth0
> :
> :
> e1000e 0000:00:19.0 eth0: registered PHC clock
> e1000e 0000:00:19.0 eth0: (PCI Express:2.5GT/s:Width x1) 1c:1b:0d:09:34:d2
> e1000e 0000:00:19.0 eth0: Intel(R) PRO/1000 Network Connection
> e1000e 0000:00:19.0 eth0: MAC: 11, PHY: 12, PBA No: FFFFFF-0FF
> e1000e 0000:00:19.0 eno1: renamed from eth0
> :
> :

On my Slackware installation, both NICs are detected and usable.
I'm just feeling uncomfortable about the MAC address abnormality.

Ztcoracat · 12-13-2016, 08:52 PM

After a short online search the only distribution that I found that supports any of the killer network interface cards is Ubuntu. And that's only some of those cards.

I don't think Slackware works with that card.