Disabled ethernet controller
 

As I start my computer and boot into debian sid linux, the lights on the lan device connector turn on and the internet connectivity is there right from beginning. But today, I found that it was turned off (the lights on the connecter was off) and ping command gave output: "destination net unreachable". I tried rebooting to the arch linux installed on the same computer but there also it remained off. I rebooted into windows and it reported that the realtek ethernet controller was disabled. I enabled it and subsequently the network got connected and worked properly in linux also.

What would have happened and how could I have corrected the problem in linux itself? Thanks for your help.

Since the adapter seems to have failed in both OS's, I would bet the problem was hardware related, and not some configuration problem. Things to look at, the ethernet cable is a good place to start. Then the ports on the switch ( router ) or modem it plugs into. Possibly the system itself, although since you didn't mention going into the BIOS to see if the hardware was still there; this is a long shot. Power outages can do some strange things also.

The command to activate an adapter is 'ifconfig'. To activated a deactivated adapter, as root, 'ifconfig eth0 up' would activate the interface called 'eth0'. ifconfig by itself will list all configred interfaces, and display their names.

Hope this helps.

Thanks for your comments. I know about ifconfig command, have used it earlier and should have tried it at that time. If I remember correctly, the ifconfig eth0 down command does not lead to LED lights being switched off at the lan connector. I will try it again tomorrow and let you know.

Agreed. The light on the lan card is hardware. If that light is out, cables, connectors etc...

When I disable from network in windows, the lights on the connector go out. This would be a sure sign that the network is fully disconnected. Can I accompalish this on linux?

Is this a laptop? If the light goes out, I believe the adapter is powered down. Can you do it in linux? Don't see why not. It would have to be done with ACPI ( Advanced Configuration and Power Interface). I have little experience with it. Some of it is the BIOS on the system, the rest is software in the OS to interface with the BIOS to control the hardware.

It is a regular desktop and not a laptop. What would be commands to disable it thru ACPI or thru BIOS?

As I stated above, I have little experience with ACPI.

BIOS, there are no commands, the BIOS has to support ACPI, look in the doc for the system.

This link may get you started.

-->http://oreilly.com/linux/command-dir...sp?path=a/acpi

The network was working all right all these days. Today, suddenly it stopped working and the LED lights at connector went off. Now the network is not working in any linux install (including live-usb) but works perfectly in windows. I have tried it repeatedly. As soon as linux boots, before the login prompt, the network connector lights go off.

How can I solve this problem? Thanks for your help.

Moderator Response
 

Moved: This thread is more suitable in <Linux-Hardware> and has been moved accordingly to help your thread/question get the exposure it deserves.

Open a command prompt, run the command 'ifconfig eth0' and post the results.

Run the command 'lsmod' and post the results.

Run the command 'lspci' and post the results.

These commands will give us some idea of the state of the adapter, the modules loaded, and the hardware itself. We'll go from there.

Here is the output:

You have the driver r8169.ko loaded. Run the command 'ifconfig eth1 up' and then 'ifconfig eth1' and post the results for both.

I had tried 'ifconfig eth1 up' but it did not work. I do not remember the exact output but it was as if eth1 was not there or not ready or not setup or not found. I will post the exact output tomorrow.

How did you configure the adapter before?

You might have a look at that, you may have a situation where the adapter was originally named eth0, now its eth1. What ever config you had for eth0 isn't being used for eth1. Try and config eth1, then give it a try.

I could now try again the 'sudo ifconfig eth1 up' command. It runs without producing any error. However, the network still is not turned on and 'ifconfig eth1' still shows same output as posted above (0 bytes and packets sent and received).

Have you configured eth1 ?

I used to install network-manager and network-manager-applet after installing any linux distribution and then add address, netmask etc to it. These are still the same while the network has now become disabled. Could you please tell clearly what exactly you mean by configuring or post a link to a suitable webpage which gives such details. Thanks.

By configure, I mean, using NM, WICD or direct editing of system files to set up eth1, not eth0. I take from your post you used NM for the configuration of eth1.

I don't use Debain, so I'm unfamiliar with system files that are used to configure ethernet adapters. I have had problems with NM in the past ( on a Ubuntu system ), so I use WICD now, or edit system files directly.

Member Response
 

Hi,

Please remember that you can always 'man command' for explanation for any bash command.

You can open a terminal and become root by 'su -' and answering password then for a static IP assignment do;
Sample '/etc/resolv.conf';
If your route is setup correctly, something like this;From 'man route';Notice the 'U' & 'G' flags from the 'man route' then look at the route sample and note the UG for eth1 gateway that is classed as 'up'.

Hope this helps!

@Onebuck:
Thanks for detailed information, steps and links. I will try these and post the feedback.

@camorri:
I do not think that the command 'ifconfig eth1 down' leads to LED lights at the LAN connector to be switched off. What command can do that? I need to use the same command to switch on the connector.

The light is controlled by hardware; as far as I know. The light goes on when there is a signal on the ethernet cable plugged into the port. You need an active device at the other end of the cable, and a good cable.

The light will go off if there is no signal on the cable. But it also goes off if you disable network in windows (try it). In my system, signal is clearly there in cable and network is working perfectly in windows but light is not turning on in linux. In linux, the light switches on very soon after booting linux, which is not occuring in my system. With 'ifconfig eth1 down', the network is disconnected but light does not go off.

I had noted this in a previous question also but at that time my network was working properly.
http://www.linuxquestions.org/questi...ection-897585/

Agreed. I pulled the cable on mine, the light goes off.

I don't have windows on my system, so I can not test this.

This works the same on my system. I have WICD installed, the interesting part for we is, if I run ifconfig eth0 down, I can still ping my router. I have to go into WICD, and press Disconnect button for things to stop working. Go into NM and disable the interface, see what the light does then.

The fact that your light does come on part way through the boot, leads me to believe there is nothing wrong in hardware.

You have Network Manager installed. Things worked normally, then stopped.

Was your interface when things worked known as eth0 or eth1 ?

If there has been a name change, due to something link a udev rule changing it, I suspect NM is messed up. I got rid of it when I ran Ubuntu on my netbook because of dumb problems like this. I replaced it with WICD for ease of use.

I went into BIOS and disabled "Onboard LAN boot ROM" and my network connection started working normallly and my problem got solved.

Should this always be disabled whenever linux is installed? Why was network working properly earlier?
It has been eth1 for a long time. Now also it has resumed to be eth1.
I tried disabling networking (top option on right clicking the network manager applet) but still the lights are on. I think the only way to reliably disconnect a linux computer from network is to unplug the cable connection.

Well, glad you got it working again. Never used, or set an option in the BIOS like that.
So, no comment there.

Best of luck with it.

After these many days when network was working well, the same problem has restarted. The network has gone off in Debian linux with LED lights at LAN connection switched off. It occurred suddenly while the system (including the network) was working properly. The network does not work even from Arch or Mint linux which are on this system. However, the lights return when I boot to windows and the network works without any problem. The output of various commands from linux are as follows:
Any help will be appreciated.

I disabled the onboard LAN and put in another ethernet card which was picked up automatically and works without a problem. Obviously, there is some hardware problem with onboard LAN.