Network card LED goes off on Booting

[George Abraham <georgeabraham@asianetindia.com>]

Hello friends,
I am trying to boot Knoppix on my brother's machine, and when I do so, 
the network LED goes off when the kernel starts probing for hardware. 
Knoppix boots and I configure networking ( IP is assigned etc ), but 
cannot ping any other machine on the network. The Ethernel card is 
detected during boot up. This card is working perfectly with Mandrake 
which is installed in the machine. Please help me how to rectify this 
problem and I want to understand why the network card LED goes off on 
booting and the machine cannot "talk" to other machines on the network. 
Thanks in advance.