Re: duplicate MAC addresses

[Rui Santos <rsantos@ruisantos.com>]

marty wrote:
> I got trouble...
> (duplicate MAC addresses)
>
> I have a Jetway atom-330 mini-itx board with a builtin NIC and 3-NIC
> daughtercard. All 4 NICS are realtek 8169. The software is recent.
> The machine works impressively except for described following issues:
>
> The builtin NIC always comes in as eth0 on boot.
> The remaining daughtercard NICS have MACS from a different sequence.
> On boot all 4 NICS are seen as unique by the kernel and assigned unique
> interrupts, (which is very nice).
>
> Enter udev...
>
> On boot udev stalls for 120+ seconds while it executes
> i801_smbus functions. This may be a unsupported hardware issue
> or other software issue but it is not normal. This may be the problem.
>
> After udev finishes the "70-persistent-net.rules" are borked and eth3 is
> assigned the MAC of eth0, causing a duplicate MAC.
> On the next boot udev sees the duplicate and renames eth3 to eth3_rename
> and the network scripts won't enable it. It becomes useless.
>
> "ip link show" always lists eth3/eth3_rename with the MAC of eth0 as below. Why?
>
> 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UNKNOWN qlen 1000
>     link/ether 00:30:18:ab:4a:8f brd ff:ff:ff:ff:ff:ff
> 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UNKNOWN qlen 1000
>     link/ether 00:30:18:ab:6a:46 brd ff:ff:ff:ff:ff:ff
> 4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UNKNOWN qlen 1000
>     link/ether 00:30:18:ab:6a:47 brd ff:ff:ff:ff:ff:ff
> 5: eth3_rename: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
>     link/ether 00:30:18:ab:4a:8f brd ff:ff:ff:ff:ff:ff
>
> What I really don't know is:
> After the kernel probes the hardware and acquires the MACs, where
> does it keep that info?
> Why doesn't udev use that correct probed kernel info for eth3, rather than
> configure eth3 with the MAC of eth0? Why probe the hardware trice?
> Where is this going wrong? I suspect i801_smbus...
>   
Hi Marty,

    I assume you have a Jetway NC92-330-LF motherboard and a Jetway
AD3RTLAN-G Daughterboard.
    If so, I also have that same hardware running and I'm experiencing
none of the issues you describe.

    I'm using a semi-stantard openSUSE 11.1 ditribution. The only change
I've made is that I'm using a 2.6.30.x kotd kernel.

    If you require any information for debugging issue, please ask.

> Marty B.
>   
Rui Santos
http://www.ruisantos.com/

Veni, vidi, Linux!