Couldn't make an internet connection using Knoppix 5.0 until I saw Duncan Macdonald's April 3, 2006 post. Now it works great. So give it a try.
Bring up a console window and enter the following commands:
su
ifconfig eth0 up
route add default gw 192.168.2.1 (or whatever the IP address of your router is)
Hope this works for you.
Peace, Earl

Fujinet 1.7.1 Atari 400 800 800XL 130XE 65XE XEGS Assembled, Tested, Working
$99.99
Atari 130 XE/Atari 1050 Bundle W/ Cords And Extras (Powered On)
$300.00
DEFECTIVE Atari 810 Vintage Computer Disk Drive powers on Unit Only Boo G3D
$49.29
Atari 800 8-bit Computer System Fully Tested Great Condition 48k READ
$350.00
INFO/soft Character Generator Manual for Atari 3000/5000/7000 NTSC
$40.00
Atari SX212 Modem for IBM Systems w/ Box, Owner's Manual & Power Adapter NOS
$125.00
Atari XE 130XE Computer NTSC with Power Supply Powers On Untested
$159.95
ATARI Mouse with Adapter for ST, STE, Mega STE, TT Optical - USA Seller
$29.99
UNOCART-2600 SD card Multi Rom Cartridge for ATARI 2600 with CASE
$34.25
Vintage Atari SF354 Floppy Disk Drive & Power Supply FOR PARTS OR REPAIR AS IS
$120.00