Just can't get internet connection working

**rollo11** · 02-19-2006, 04:56 PM

"From zero to Linux in 5 minutes".. Yeah, plus 17 hours to get internet access with it... But yeah, I know, that's the deal with Linux sometimes.

Anyway I've now spent days trying without joy to get Knoppix to see my cable internet connection. Here's the situation, if anyone could help me out here:

on startup my laptop's ethernet port is detected and the module via-rhine called correctly; this shows with lsmod
ifconfig only shows the loopback device lo, so I do ifconfig eth0 up and then eth0 shows too
but ifup eth0 returns "Ignoring unknown interface eth0=eth0", so...
I add the line "iface eth0 inet dhcp" to /etc/network/interfaces (why doesn't Knoppix do this?); DHCP is definitely functional upstream, because the cable is the same as for another DHCP-using machine

So everything looks right at last. I do ifup eth0. There is a pause and then:

Code:

Operation failed. Failed to bring up eth0

I would really appreciate pointers on where to go from here. Thanks.

**OErjan** · 02-19-2006, 06:12 PM

does your card get detected at all? lsmod and lspci will help with that.
aswell as dmesg|grep eth
give us the output from those. it will help us help you.

**rollo11** · 02-19-2006, 06:53 PM

Hey OErjan, thanks for the response.

Code:

root@0[knoppix]# lsmod
[...]
via_rhine   23172   0
mii   8320   1   via_rhine
[...]

Those are the ethernet modules I believe.

Code:

root@0[knoppix]# lspci
[...]
0000:00:12.0 Ethernet controller: VIA Technologies, Inc. VT6102 [Rhine-II] (rev 78)
[...]

There's the ethernet controller. Both those outputs I have edited because I am copying them by hand to my connected machine.

Code:

root@0[knoppix]# dmesg|grep eth
eth0: VIA Rhine II at 0xd0002c00, 00:40:ca:da:c1:8f, IRQ 23.
eth0: MII PHY found at address 1, status 0x7849 advertising 05e1 Link 0000.
eth0: link down

What do you think?

**OErjan** · 02-21-2006, 05:44 PM

sorry for late reply. it seems like you have a fairly straightforward via rhine card, i have one myself. this works just great with linux.
it should be enough to just type sudo pump in a console to get networking if what you say is true.
or better run trought netcardconfig (penguin menu and networking)
and i would also check if you have a MAC filter in your router, that may block things,
the adress MAY differ between WIn and Linux (i am talking about this part; 00:40:ca:da:c1:8f).

**Harry Kuhman** · 02-21-2006, 05:57 PM

Answer #4 would have saved 17 hours of work plus whatever time you have spent posting. Under $10 AR this week at CompUSA.

**Harry Kuhman** · 02-21-2006, 06:02 PM

Originally Posted by rollo11

I add the line "iface eth0 inet dhcp" to /etc/network/interfaces (why doesn't Knoppix do this?); DHCP is definitely functional upstream, because the cable is the same as for another DHCP-using machine

What do you mean by another DHCP-using machine? Are you trying to hook two computers directly to cable without a router? What happens if you just boot Knoppix in that "another machine"? I still suggest my answer #4 above.

**rollo11** · 02-21-2006, 07:33 PM

Thanks for your latest OErjan.

Originally Posted by OErjan

it should be enough to just type sudo pump in a console to get networking if what you say is true.

Code:

$ sudo pump
Operation failed.

or better run trought netcardconfig (penguin menu and networking)

Code:

Sending DHCP broadcast from device eth0 Operation failed.
Failed.
Hit return to exit.

In both of these there was a pause before the operation failed.

and i would also check if you have a MAC filter in your router, that may block things,
the adress MAY differ between WIn and Linux (i am talking about this part; 00:40:ca:da:c1:8f).

There is no router, only a cable modem, and I don't run Windows. My other machine (with which I am hotplugging the cable) runs Suse and uses an 8139too ethernet card. It connects by DHCP no problem.

What's the next step? The error messages are unhelpful. Can I assume that the problem lies with the DHCP config? Maybe give it more time to search? This is driving me nuts, I just want to use my new machine! I know, must be patient and methodical...

**rollo11** · 02-21-2006, 07:41 PM

Originally Posted by Harry Kuhman

What do you mean by another DHCP-using machine? Are you trying to hook two computers directly to cable without a router? What happens if you just boot Knoppix in that "another machine"? I still suggest my answer #4 above.

Thanks Harry for your messages. I appreciate that a router is a good technical solution, but it does cost money (at least $ 30 here in France) and it means another box and wiring. I am just trying to connect a single laptop to the internet. It's possible in Suse (and Windows of course), and call me a masochist but I want to make it work in Knoppix too!

The cable I am switching between machines until I can get the connection working. There is no network.

**Harry Kuhman** · 02-21-2006, 09:26 PM

Originally Posted by rollo11

....It's possible in Suse (and Windows of course), and call me a masochist but I want to make it work in Knoppix too!

The cable I am switching between machines until I can get the connection working. There is no network.

It certainly can be done with Knoppix too. In fact most of the time with cable (as opposed to DSL) it just works. But some cable systems do strange things, like remember the mac address of the system they were talking to and refuse to talk to a different computer. I don't know if yours does that or not, and it's only one example of what might be going wrong. But it is why I asked what happens if you boot Knoppix on the other computer, which I don't think you responded to. Of course, a router will let you resolve this and the cable company will only see the router's MAC address, or you can tell it to mirror the mac address of the current working system so you don't have to get them to accept a new mac address for the router.

If both computers have PCI NICs you could try swapping the NICs and see if the Knoppix computer will go on-line then (and if so I bet the Windows box no longer will).

I have to mention (again) that I spent over $100 for my first router. It was wired only, and I was out of work at the time. It was still a good and important investment, even though it now lives in my travel pack and has been replaced by a wireless router at home. I would never run a windows system on a high speed connection without the protection of a NAT router; that's just crazy and begging for infection or worse. So even if you can't get the occasional killer price deal we sometimes see, I don't understand the reluctance to buy this important piece of equipment.

**rollo11** · 02-22-2006, 12:28 AM

Guys, you solved it. Thanks so much, both of you.

Yep, it was the MAC address that was the problem. My cable company was obviously only accepting DHCP requests from the MAC address of the other machine's ethernet card. So I followed your hint and used the command

Code:

ifconfig eth0 hw ether 00:01:02:03:04:08

(see http://en.wikipedia.org/wiki/Mac_address ) to change the MAC address on the new machine to the same. And presto, DHCP works.

Thanks again, I really appreciate you taking the time to figure this out with me.

PS Harry, I couldn't boot Knoppix on my other machine because it doesn't have a DVD drive. Should've mentioned this.