I have knoppix 3.9 installed and had some problems with lo configuring. I was able to fix per the documented bug here:
http://www.knoppix.net/wiki/Bugs/3.9-2005-05-27 (#15)

After rebooting if I perform ifconfig -a, my loopback is set up as it should 127.0.0.1, but now I cannot connect to my DSL.

In the past, I always had to type in pump -i eth0
and my connection to the internet would work.

Now I get a "failed operation" when I do that. I have also tried ifup eth0, and it reports back that it is an 'unknown' device.

Im lost as to what to do now, to get eth0 configured so that I can use my DSL.

Any pointers?

Thanks

Jerry