On Thu, May 10, 2012 at 11:50 AM, Gregory P. Ennis PoMec@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.