HOWTO FIX no link detected Realtek 8168/8169 cards

[noob12]

A number of users have been independently reporting an issue where they see no link detected and/or no link light on their Realtek 8168/8169-based wired ethernet cards when booting Ubuntu on a dual-boot Windows host. The card works in Windows but in Ubuntu it shows no link light and ethtool reports no link detected. (This can also affect you on initial installation of a single-boot system, but after running Windows on the host.)

Several users have now reported that this works for some Realtek 8139 cards as well.

(You can check if you have this type of card by typing the command lspci -nn and looking for your wired ethernet card in the list.)

Here is a fix for the most common causes.

First check that your ethernet cable is connected at boot. There is a known bug in the Ubuntu driver for this card that the cable must be connected to an active link at boot time for the card to work (https://bugs.launchpad.net/ubuntu/+s....20/+bug/86798)

If your ethernet cable is connected at boot time and you are experiencing the no link problem, try this: Shutdown, power down. Unplug your host (this cuts power to the card if wake-on-lan power is maintained). Wait 15 seconds. Plug in. Boot ubuntu.

If that routine works, you are probably affected by the following (excerpt from gentoo wiki http://gentoo-wiki.com/HARDWARE_RTL8168). Note the second and third paragraphs. Then read the Windows-side workaround/solution in the first paragraph.

As of 27 May 2007, in kernel 2.6.21.3, you may experience the issues with the r8169 driver if you dual boot Windows on some systems. Windows by defaults disables the NIC at Windows shutdown time in order to disable Wake-On-Lan, and this NIC will remain disabled until the next time Windows turns it on. The r8169 driver in the kernel does not know how to turn the NIC on from this disabled state; therefore, the device will not respond, even if the driver loads and reports that the device is up. To work around this problem, simply enable the feature "Wake-on-lan after shutdown." You can set this option through Windows' device manager. Edit: Problem with dual-booting with Windows exist also in 2.6.19.5 and 2.6.20.8 kernel, so it is safe to assume that it will concern all 2.6 kernels until the kernel developers update the drivers for RTL8168 to the version that will be able to turn on the NIC from disabled state. (Corey) Second edit: Powering off and unplugging the machine for a few seconds (around 10 usually does it) seems to reset the card, so it will work in Linux again until you boot Windows again.

ADDED NOTE: Please use the poll above only if your situation actually matched the one described here (same symptoms, same hardware and dual boot)

[peterroots]

I seem to have what seems like the same problem using a Toshiba texra with an
Intel Corporation 82801DB PRO/100 VE (MOB) Ethernet Controller (rev 83) (according to lspci)
and also with a Xircom realport ehternet10/100 pcmcia card.
This solution did not work for me (the inbuilt card worked initally but then stopped but still works in windows). I tried the toshiba control, hardware setting to select wake on lan enabled and also tried in the hardware section of mycomputer-> properties.
the xircom had no wake on lan setting and the built in card had opitons of dissabled, os control or force. I tried force first of all then tried os controlled. Niether worked
If anyone out there has any ideas they would be greatfully received.
(an old Dlink DE-650 seems to work fine).

[noob12]

Please do start a new thread if your situation doesn't match the one here (meaning you don't have the same symptoms and same hardware in a dual boot situation with Windows). It probably requires completely separate diagnosis. I and others on the forum will help.

[peterroots]

Thanks for your comment, I posted here as the situation seemed the same just slighly different hardware.
Anyway the problem is now solved, only thing is I am not sure which extra things I did acutally fixed it and which were superfluous!
First I am using a Toshiba Tecra (not a texra - finger slipped yesterday!)
After trying the suggested fix and rebooting both with and without an active net connection plugged in to either the built in port or the plug in port I had no network connection and the built in port did not show up on the knetworkmanager. Stoped and started knetworkmanager several times with and withought the net cable plugged in - no change
In settings network, I could see the built in but realised it was no longer activated on boot so I changed this an rebooted - still did not work but was visible on knetworkmanager.
stoped and started knetworkmanager again - still no luck.
I then selected manual settings on knetworkmanger and found that here the card was not acitvated on boot even though I had changed it on system settings network! so I changed that as well and rebooted again (with a net cable plugged in).
This time it all worked.
Now I can plug and unplug network cables to my hearts content and things work as they had originally (just after installing Kubuntu)
So many thanks for pointing me in the right direction!

[3ntity]

Thanks, this did the trick

[toketin]

i've tried to do it in windows, because i've a network card, Dfe-528Tx of D-link that uses the modules 8139cp and 8139too, it's seen by ubuntu, but the system doesn't recognize it, maybe it's a problem with windows, i've tried but the adavanced option of my card are these:

the second and the last three option are enabled but ubuntu doesn't still recognize the card.... how can i do?

[noob12]

This fix will only work for the specific problem whose symptoms are described here; everything will look right (you'll see the interface in ifconfig -a) but ethtool will show that you don't have a link detected, and the shutdown/unplug test will solve the problem. If the shutdown/unplug test didn't work for you, you probably have a different problem. If you post a new thread with the details and PM me, I'll try to help you.

[SpiritIsReality]

howdy
noob12 ... thankyou sooo much for being here.
I found hope here on a search.
pals

[SpiritIsReality]

howdy
>If your ethernet cable is connected at boot time and you are experiencing the no link problem, try this: Shutdown, power down. Unplug your host (this cuts power to the card if wake-on-lan power is maintained). Wait 15 seconds. Plug in. Boot ubuntu
>>unplug your host from the power source. thanks

[jcordone]

Hello,

I have an Acer Aspire 5100 laptop with a RTL8139/810x (according to Windows) network adapter. A while ago it stopped working for Ubuntu. After trying everything I could think of, including reinstalling Linux, I finally tried what works to reset most machines. I unplugged everything from my laptop, including the power cord, and removed the battery for a few seconds. After reinstalling the battery, and reattaching everything, the network adapter worked fine under Linux.

Every single time that I boot from Windows XP, my network adapter will not work under Linux again, until I finally unplug and remove the battery to reset it! This seems to reset something in my system so that Linux can use the network card again. And I can reboot between Linux sessions, without any problems, however, after booting Windows just once, it will not work again under Linux, unless I reset it as described above.

I don't remember if I downloaded any windows updates before this started happening, but it makes one wonder, just a bit.

--jcordone