Internet connection problems

[Rostin]

I'm trying to use Knoppix 5.0.1 live CD. I have an ABIT AV8 mobo, and I'm using the onboard NIC. There's no other NIC in the computer.

The trouble I'm having is that I can't get on the internet.

As knoppix boots, it appears to detect two NICs: eth0 and eth1. If I run "ifconfig -a", I get this output:

eth0      Link encap:Ethernet  HWaddr 00:50:8D:D7:62:CF  
          inet addr:24.206.166.202  Bcast:255.255.255.255  Mask:255.255.255.128
          inet6 addr: fe80::250:8dff:fed7:62cf/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:607 errors:0 dropped:0 overruns:0 frame:0
          TX packets:19 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:44620 (43.5 KiB)  TX bytes:3046 (2.9 KiB)
          Interrupt:19 Base address:0xf200 

eth1      Link encap:UNSPEC  HWaddr 00-02-3C-00-21-09-21-8A-00-00-00-00-00-00-00-00  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:4 dropped:4 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:24 errors:0 dropped:0 overruns:0 frame:0
          TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1572 (1.5 KiB)  TX bytes:1572 (1.5 KiB)

sit0      Link encap:IPv6-in-IPv4  
          NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

I can't ping anything until I use the command "ifconfig eth0 up". Then, I can only ping if I specify the interface: "ping -I eth0 <ip>"

Another strange thing is that I've used other versions of Knoppix before, and didn't have this problem. Other live CDs I've tried (DSL, for example) wouldn't work, either.

I'm sure this is something simple, but I know very, very little, and I would appreciate the help.

[Rostin]

When I say I can't get on the internet, I mean that I can't browse the web. Also, in case it wasn't clear, I can only ping using IP addresses.

[Rostin]

I connect directly to my cable modem.

[Rostin]

I dug around a while longer in the forum and found out how to set up my default gateway.

route add default gw <ip>

That took care of the problem. I don't understand why Knoppix isn't setting this up itself, but whatever.