[CentOS] Forcing ifcfg-eth0 to use the same nic in multi nic machine

Mon Aug 13 19:27:40 UTC 2007
Brian Mathis <brian.mathis at gmail.com>

On 8/13/07, Doug Coats <dcoatshca at gmail.com> wrote:
> I am new to CentOS (coming from Fedora) and I really like it!
>
> I am having difficulty getting one of my machines to boot and assign
> the same designation of eth0 and eth1 to the same nics consistantly.
>
> I have an MSI motherboard with 2 nics on the board.  Strangely enough
> both nics report the same MAC address.  This is not an issue since I
> use the computer to route between two different subnets so they don't
> see each other on the network.
>
> The problem comes when I reboot and they race against each other to
> see which one will get to be eth0.  If they switch my routing dies and
> I loose access with out rebooting and hoping they switch back or
> switching the actual cables.
>
> I have googled and searched my networking resources but all of the
> fixes that I have found focus on using the MAC address to solve the
> problem but in my case they are the same.
>
> The only difference is that they use different drivers.  One is a
> Realtek and other is a Marvell.
>
> I have turned off Kudzu or they reconfigured every time a booted the
> machine.  It only happens every once in a while but I need it to be
> consistent.
>
> Any suggestions or pushes in the right direction would be most appreciated.
>
> Doug Coats


As far as I understand networking, if you only have 1 MAC, you only
have 1 NIC.  You might have 2 connectors, but that seems really
strange.  It seems like this is some sort of undefined behavior.  I
think that having only 1 MAC really *IS* an issue.

Is it possible they are set up to do of link teaming or something like that?

My suggestion is to get another network card.