ethernet problem

[jjanderson5]

I've been running Knoppix 3.7 from CDROM on my
PC for about 2 months. Things were running fine until
last week when the power when out. When I rebooted the
PC, there was no connectivity to the network. When
I ran ping, I got the error message: "Network cannot be reached".

My configuration on the my network looks something like this:

phone line --> DSL modem
--> ethernet --> router
--> ethernet --> PC


I've been assuming that the problem is with the ethernet
hardware interface, because when the PC boots up, the
ethernet looks like it starts ok as the log messages scroll by.

When I called the manufacturer, the tech support guy said
I need to check that the driver is installed ok. My understanding
is that Knoppix detects the ethernet interface at boot time and
automatically loads the driver. And if the driver was ok
on prior boots, it should be ok now.

Am I correct? Is there anything else I can do to isolate this
to hardware, or to software?

Jim Anderson

[Harry Kuhman]

phone line --> DSL modem
--> ethernet --> router
--> ethernet --> PC

Is there just one PC attached to the router? I have a hunch that the router may need to be reset (or at least powered down and back up). But a few more questions: Can you get the router to respond to another PC? Can you get the router to respond to another PC on this network cable and port? Can you boot this PC into Windows and does the network work there? If this PC is running an installed Knoppix, can you boot your Knoppix CD and does that behave any differently?

[jjanderson5]

I have 4 Windows PCs and 1 Redhat Linux PC attached to the network besides the Knoppix PC.
All work fine on the network. The Redhat PC is a laptop. I had swapped the ethernet cables
and the Red Hat PC continued to work and the Knoppix PC failed to respond. Unfortunately,
the Knoppix PC does not have windows running on it, so I can't reboot to see if windows network
is ok. At this point, I have not installed Knoppix on the hard disk, so all of my activity is off of the
CDROM.

[Harry Kuhman]

....Things were running fine until last week when the power when out. When I rebooted the
PC, there was no connectivity to the network. When I ran ping, I got the error message: "Network cannot be reached"....

I have 4 Windows PCs and 1 Redhat Linux PC attached to the network besides the Knoppix PC.
All work fine on the network. The Redhat PC is a laptop. I had swapped the ethernet cables
and the Red Hat PC continued to work and the Knoppix PC failed to respond. Unfortunately,
the Knoppix PC does not have windows running on it, so I can't reboot to see if windows network
is ok. At this point, I have not installed Knoppix on the hard disk, so all of my activity is off of the
CDROM.

OK, if those ports are working for other computers than it does not sound like the router needs resetting. Quite a strange problem.

My first guess is the NIC itself has failed, but before rushing to swap that I do have a few additional thoughts: You haven't told us what make and model of router you are using, and at this point that might become a factor. If your router has any feature in it to limit access based on MAC address, or to hand out IP addresses based on MAC address, you might want to turn off that feature and try again. If that doesn't fix anything then I would try changing out the NIC in the computer or, better yet, swapping that NIC into one of the working computers and using a known good NIC in the Knoppix computer. See if the problem moves with the NIC or if it stays with the Knoppix computer.

Please post back even if you resolve the problem.

[pulsar]

To check things out you can temporary make a straight connection from your pc to the internet (cut out the router).

[Harry Kuhman]

To check things out you can temporary make a straight connection from your pc to the internet (cut out the router).

He has already said that it is a DSL modem, so that would also involve him needing to get involved with PPPoE on his Knoppix system, account login and the rest. I see no point in doing ths, and it doesn't really get him any closer to solving the problem that he really wants to solve.

I do hope we hear back from jjanderson5, it is a strange and interesting problem.

[jjanderson5]

I'm sorry to take a while to reply. My plumbing broke and I've been battling that
for the past 2 days. At least that is working again

Anyway, to answer the question about the router, it is a Linksys BEFSR41. But I don't
see how MAC addressing could be the problem since everthing was working prior to the
power failure.

Unfortunately, the ethernet interface is on the motherboard, not a separate card.
The tech support guy for the manufacturer suggested that I add a NIC to the PC
and give it a whirl. Unfortuneately, I don't have a spare card at this time. I may
buy one just to try it out.

BUT, I think we are just getting to my original assumption, which is that the
ethernet interface hardware has failed. And also back to my original question

My understanding
is that Knoppix detects the ethernet interface at boot time and
automatically loads the driver. And if the driver was ok
on prior boots, it should be ok now.

Am I correct?

I would really like to understand when and where the driver is loaded by
Knoppix so that I can convince the manufacturer that the problem is a hardware
problem. It seems to me that it cannot be a driver program, but I would
like someone knowledgeable about knoppix agrees with what I'm saying.

Jim[/quote]

[Harry Kuhman]

..... And also back to my original question

My understanding is that Knoppix detects the ethernet interface at boot time and
automatically loads the driver. And if the driver was ok on prior boots, it should be ok now.

Am I correct?

I would really like to understand when and where the driver is loaded by
Knoppix so that I can convince the manufacturer that the problem is a hardware
problem. It seems to me that it cannot be a driver program, but I would
like someone knowledgeable about knoppix agrees with what I'm saying.

Jim

My understanding could be wrong, but I thought the driver was compiled right into the kernel. Maybe others who know more than I will join in. Whatever the case (compiled into the kernel vs. detected and loaded at boot), if the system and Knoppix used to work it should certainly still work. You are still using the same boot command as before the power fail, are you not? (knoppix vs knoppix26?)

..... it is a Linksys BEFSR41. But I don't
see how MAC addressing could be the problem since everthing was working prior to the
power failure.

Just working on a hunch here. We have seen some strange problems that present similar symptoms where a router sees a different mac address when running Knoppix than when running Windows and will not respond to the computer running Knoppix. It's still not understood (at least by me) why the mac addres is being changed. So if there is anything going on in the router that is limiting access by mac address, try disabling it. I have the same model router and it does not have any MAC address based control in it. But I'm running very old firmware in mine, when I use it at all, so you could well have such a feature with newer firmware.

[jjanderson5]

I did not see anything on the router admin screen that allows me to limit MAC address.
So I don't think that is the problem. Even if there were such a problem, wouldn't that
have caused my PC to have never worked with Knoppix?

Your response regarding the driver confirms more or less what I thought. Regardless
of whether the driver is compiled it or loaded at boot, the driver is on the CDROM and
could not be corrupted on the harddisk. The tech support guy wanted me to check that
the driver was not corrupted on the harddisk, so I can safely answer 'no'. I think it
very unlikely that the driver is corrupted on the CDROM, but you never know

At any rate, my next step is to buy a new ethernet card and try that on my system.
I'll probably buy off the internet, so it may be a week or two before I post with results
on the new ethernet board.

I want to thank both Harry and "pulsare". You have been a big help is clarifying what
is going on here!!

Jim

[Harry Kuhman]

...... Even if there were such a problem, wouldn't that have caused my PC
to have never worked with Knoppix?

You would think so, but as I stated above sometimes it seems that Knoppix ends up using a different MAC address than Windows on the very same hardware. See this thread for an example: http://www.knoppix.net/forum/viewtop...er=asc&start=0
The symptoms are close enough to yours that without knowing what router you were using it was worth asking.

Edit: OK, on rethinking what you said, yes, it would seem that whatever mac address Knoppix was using it should always have used. But since we (I) don't understand why Knoppix is changing the MAC address, I can't say for certain that this change happens all of the time. So it was just something worth looking at.

Please post back when you have it working, and post back if you ever get the on-board NIC working with Windows or anything else.