[CentOS] How Do I ...

Wed Apr 14 21:23:09 UTC 2010
Kahlil Hodgson <kahlil.hodgson at dealmax.com.au>

On 04/15/2010 12:58 AM, gene.poole at macys.com wrote:
> I've got a machine running CentOS 5.3 and this machine has got 2 -
> built-in 1 Gig NICs and a expansion card with 4 - 100 Meg NICs.  For
> whatever reason at install time, it made the expansion card eth0 through
> eth3 and the internal ports eth4 and eth5. And by default the 'machine'
> is known on the network by the eth0 NIC, so my throughput is limited to
> 100 Mb.  How can I force the internal NICs to be eth0 and eth1?

I had a similar problem when an onboard NIC died on me and I had to
shuffle ports to keep things running while I went shopping for a new
mainboard.  Port numbers are assigned by udev during startup and
assignment is initially somewhat arbitrary and udev may shuffle the
ports around by calling /lib/udev/rename_device.  That program looks at
your ifcfg-ethX scripts in /etc/sysconfig/network-scripts for lines like

    DEVICE=eth4
    HWADDR=00:e0:4c:50:19:95

Therein lies your solution. Use, say, 'ifconfig' to map out the current
HWADDR lines, and edit (and/or rename) the ifcfg-ethX scripts to suite.
 Just be sure to keep the DEVICE setting in sync with the name of the file.

Hope this helps,

Kal