CentOS - May 2012 - eth1 - Centos 6.2 - changing names of network interfaces

Everyone,

Can anyone refer me to a tutorial as to how to rename the network cards,
ie I have one that ended up being system-eth3, that I want to be
system-eth1?

I am setting up a new CentOS 6.2 system that I plan to use as a gateway
and e-mail server.  The original machine had only one nic card, and to
my surprise the vendor did not have a 1000/100/10 card that would fit in
the pci-e slot.  I ordered a pci-e network card, and while waiting for
it to arrive I purchased a Sabrent usb 1000/100/10 to finish my
development.  I was able to get CentOS 6.2 to recognize the usb ethernet
adapter which had been assigned system-eth1, but I could not get data to
go through it (in or out).

The pci-e network card came in, and after it was installed, and upon the
next boot it was assigned system-eth2.  I tried to delete the usb eth1
and reassign the pci-e to eth1, but have managed to really mess things
up.  I deleted references to eth1 and eth2 in :
 
/etc/sysconfig/networking
/etc/sysconfig/network-scripts

hoping that the next boot would reassign the pci-e network card as eth1,
but now the system will not even recognize the new card.

Is there any way to reset the numbering sequences of network cards so
that I can have the the desired names.  I wish now I would have left it
alone, and just changed references to eth1 to eth2 in my iptables
firewall.  

Thanks much,

Greg Ennis

Just went through this last night UUID is involved now this should help -
https://alteeve.com/w/Changing_the_ethX_to_Ethernet_Device_Mapping_in_EL6

On Thu, May 10, 2012 at 11:50 AM, Gregory P. Ennis <PoMec at pomec.net>
wrote:
> Everyone,
>
> Can anyone refer me to a tutorial as to how to rename the network cards,
> ie I have one that ended up being system-eth3, that I want to be
> system-eth1?
>
> I am setting up a new CentOS 6.2 system that I plan to use as a gateway
> and e-mail server.  The original machine had only one nic card, and to
> my surprise the vendor did not have a 1000/100/10 card that would fit in
> the pci-e slot.  I ordered a pci-e network card, and while waiting for
> it to arrive I purchased a Sabrent usb 1000/100/10 to finish my
> development.  I was able to get CentOS 6.2 to recognize the usb ethernet
> adapter which had been assigned system-eth1, but I could not get data to
> go through it (in or out).
>
> The pci-e network card came in, and after it was installed, and upon the
> next boot it was assigned system-eth2.  I tried to delete the usb eth1
> and reassign the pci-e to eth1, but have managed to really mess things
> up.  I deleted references to eth1 and eth2 in :
>
> /etc/sysconfig/networking
> /etc/sysconfig/network-scripts
>
> hoping that the next boot would reassign the pci-e network card as eth1,
> but now the system will not even recognize the new card.
>
> Is there any way to reset the numbering sequences of network cards so
> that I can have the the desired names.  I wish now I would have left it
> alone, and just changed references to eth1 to eth2 in my iptables
> firewall.
>
> Thanks much,
>
> Greg Ennis
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>

On Thu, May 10, 2012 at 11:50 AM, Gregory P. Ennis <PoMec at pomec.net>
wrote:
>
> Can anyone refer me to a tutorial as to how to rename the network cards,
> ie I have one that ended up being system-eth3, that I want to be
> system-eth1?
>
> I am setting up a new CentOS 6.2 system that I plan to use as a gateway
> and e-mail server. ?The original machine had only one nic card, and to
> my surprise the vendor did not have a 1000/100/10 card that would fit in
> the pci-e slot. ?I ordered a pci-e network card, and while waiting for
> it to arrive I purchased a Sabrent usb 1000/100/10 to finish my
> development. ?I was able to get CentOS 6.2 to recognize the usb ethernet
> adapter which had been assigned system-eth1, but I could not get data to
> go through it (in or out).
>
> The pci-e network card came in, and after it was installed, and upon the
> next boot it was assigned system-eth2. ?I tried to delete the usb eth1
> and reassign the pci-e to eth1, but have managed to really mess things
> up. ?I deleted references to eth1 and eth2 in :
>
> /etc/sysconfig/networking
> /etc/sysconfig/network-scripts
>
> hoping that the next boot would reassign the pci-e network card as eth1,
> but now the system will not even recognize the new card.
>
> Is there any way to reset the numbering sequences of network cards so
> that I can have the the desired names. ?I wish now I would have left it
> alone, and just changed references to eth1 to eth2 in my iptables
> firewall.
>
The kernel sets the names of the devices according to the rules in
/etc/udev/rules.d/70-persistent-net.rules (which will be recreated at
reboot if you delete it after a change).   The
/etc/sysconfig/networking-scripts/ifcfg-xxx files have to match the
DEVICE= and HWADDR= entries to work.  Sometimes the old ifcfg-xxx
files will be renamed with a .bak extension and new ones created. When
that happens I keep the new HWADDR= entry but all of the other content
from the .bak file to make it work again.

-- 
   Les Mikesell
    lesmikesell at gmail.com