PDA

View Full Version : Renaming network interfaces



monkeyman2000
09-12-2004, 09:06 PM
Hi,

I am using an HD install of knoppix 3.4 and am having some trouble getting the network interfaces to behave.

The machine in question is a laptop with a built in ethernet and sometimes a pcmcia wireless ethernet card. The kernel sometimes names the built in ethernet eth0 and the wireless eth1, sometimes the reverse, depending on whether the pcmcia card is inserted at boot time or is put in later. Both interfaces work fine, but the naming is inconsistent.

This is problematic for varous reasons. First, the built in ethernet (often) uses a static IP address which is set up in /etc/network/interfaces. This doesn't work when the built in ethernet has an interface name different that expected.

I am also using the laptop-net package to manage the built-in ethernet. This only works (as far as I can tell) when you know the interface name.

Some research showed that the use of the nameif utility seemed be called for. This program renames network interfaces based on mac addresses, just what I need, but I haven't been able to get it working. I set up a correct /etc/mactab file and inserted '/sbin/nameif -s' in /etc/init.d/networking; I also inserted the command in /etc/init.d/knoppix-autoconfig to run prior to the starting of the cardmgr. None of this seems to work, however. As far as I can tell nameif is either not running or is ignored; the kernel insistes on naming the interface as it wants.

Can anyone help me get my network interfaces consistently named?

monkeyman2000
09-13-2004, 11:59 PM
I solved this problem. There were actually a couple of problems. First, I had to turn off the dhcp section in the /etc/init.d/knoppix-autoconfig script. I did this by adding the 'nodhcp' option to my boot parameters. This script was running pump before nameif had a chance to rename the interfaces... now I just let the modified /etc/init.d/networking take care of bringing up the interfaces.

The other issue was with a pcmcia interface. This interface is acutally brought up and down by cardmgr, so I had to modify the /etc/pcmcia/network.opts file to have it run nameif right before bringing the interface up.

Now I have both my intrefaces renamed, and named consistently. Hope this info might help somebody else.



References for the basics of nameif:

Naming Network Interfaces
http://www.linuxfromscratch.org/hints/downloads/files/nameif.txt


10.9 Dealing with inconsistent naming of interfaces by the kernel
http://www.debian.org/doc/manuals/reference/ch-gateway.en.html