I guess I wasn't clear enough in my questioning.

The PC connected to the internet normally runs w2k and is the server for the ICS for the windows 98 PC. (both PC's can use the same internet connection) When I'm running Knoppix (from CD!) on the w2k machine, there is NO more internet connection for the w98 PC.
I want the w98 machine to be able to use the internet connection, but since w2k isn't running, it's Knoppix that should do the job. The Knoppix (w2k) PC has 2 nic's: 1 for the internet connection (eth0) (sorry, I had this wrong in my 1st mail) and 1 for the connection with the w98 (eth1 with ip 192.168.0.1) The w98 PC has 1 nic. When w2k is running the w98 PC always gets it's IPassigned automatically 192.168.0.134 (I don't know why this is not 192.168.0.2 as I should expect but I'm absolutely not an expert in these things)