[SGVLUG] Random MAC address.

[Claude Felizardo]

On 5/29/07, Sean O'Donnell <sean at seanodonnell.com> wrote:
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> I have noticed that my NIC cards keep getting 'shuffled' when I reboot.
>
> e.g. Sometimes the WAN NIC boots up as 'eth0', and sometimes it boots up
> as 'eth1' instead.
>
> I have multiple NICs installed, so it gets a bit annoying trying to
> figure out which is which after rebooting.
>
> My iptables/ip_forward (firewall/router) and dnsmasq
> configuration-scripts assume that the WAN NIC is always 'eth0', so when
> it switches to eth1, I have to physically modify and re-execute them.
> *shrug*
>
> This is obviously inefficient, as I sometimes need to reboot my system
> remotely, which will cause my system to be exposed (w/ out firewall),
> and may even prevent me from reconnecting to fix it (until I get home).
>
> I'm using an Abit KN9 SLI board w/ an Athlon X2 3800+ CPU. I just
> recently built this box and haven't rebooted more than a few times so it
> hasn't become a big deal yet, but I would like to know how to fix this
> before it gets any more annoying.
>
> I wonder if this has something similar to do with what Michael's problem
> is, perhaps the same (or similar) solution?

Well while looking around at my problem, I noticed a few files called
/etc/iftab and I think it was /etc/mactab.  Don't recall if they were
on both disks much less which version of mandrake had which file but
the entry looks something like this:

eth0    mac xx:yy:zz:aa:bb:cc

and it's suppose to let the system know which device should be
assigned to which NIC.  Alternatively I think you can update the entry
in /etc/sysconfig/network-scripts/ifcfg-eth0 and specify the mac
address there.  I had to do something like this when I rolled my own
firewall but stopped doing so when I switched to a COTS solution.

also try man page on nameif

claude