no network after logging

If you restart the network-manager service, is it OK?

No, nothing happens. I can see my wired connection on the live cd session but no connection when I log in properly. (ubuntu 10.04)

Is the install fully updated?

Ubuntu 10.04 is in end of live status. There is no support any more.
I suggest you do a new installation with a supported version.
You can use the live system and an external device to create backups of your private files for restoring them afterwards.

I'm very sorry for my mistake. I have 14.04. Still have to do a new installation? My file is encrypted. I can't create a backup. There is no way to fix my internet connection?

I updated the system regularly. No problems with that.

If you don't have Ubuntu 10.04 but 14.04, then please ignore my previous message.

What kind of connections do you have?
I assume the problem is with a wireless connection.
Are you able to connect your computer to the router with a cable?
Then try steps 1 to 6 in https://help.ubuntu.com/community/WirelessTroubleshootingProcedure and paste the information into this question document that you have already created.

No, I'm afraid the problem is with the wired connection. There is no installation for wireless connection on my computer. I only use a cable. The router is ok, I know this because I can connect with my mobile wireless connection there. The computer is like there is no internet connection on it. I write this through a live cd, the internet connection appears there, that means is no problem with the hardware.
Thank you for trying to help!

What Ethernet chip are you using?

I have the same problem!
PC and Notebook both work under Ubuntu 14.04.3. After updating oxideqt with its libraries (29.01.2016) and rebooting afterwards Network Manager completely died. Rebooting doesn't help. NMCLI refuses to start because Network Manager has no version number. I cannot even send the crash report because I have no connection to the net. Neither Ethernet (PC) nor Wi-Fi (Notebook).
Moreover the Notebook has completely fresh install (some weeks) without synchronizing AppCenter with PC!
Even now for writing this I booted from LiveCD.

PLEASE HELP!

P.S. I cannot understand how but today (31.01.2016) both my computers started "telling" me that they've found new software updates without any connection to the net. When I tried to install these updates they finished unsuccessfully because they require to be installed from sources without authorization!

Karu, please make your own question.

Thanks

Well, I have done this! But I thought that we had the same problem and my information would help to solve it!

This seems to be caused by Bug #1511735

Do you have the trusty-proposed repository enabled?
There is a new version of libnl3-200-* that apparently does not correctly work together with all versions of network-manager, and this seems to be one of the cases, where the users of the -proposed bucket run into a problem that was not detected earlier.

Proposal for workaround:
downgrade libnl-3-200 libnl-genl-3-200 and libnl-route-3-200 from 3.2.21-1ubuntu1 to 3.2.21-1

If you do not have a working network connection, you can check if you have the old version still available in the apt cache.

Which architecture is your system?

if it is i386, then you might try a commands like

cd /var/cache/apt/archives
sudo dpkg -i libnl-3-200_3.2.21-1_i386.deb libnl-genl-3-200_3.2.21-1_i386.deb libnl-route-3-200_3.2.21-1_i386.deb

If you don't have copies of these files in your apt archive any more, you should be able to download them from https://launchpad.net/ubuntu/+source/libnl3/3.2.21-1/+build/5320738

For amd64 the file names are
libnl-3-200_3.2.21-1_amd64 .deb libnl-genl-3-200_3.2.21-1_amd64 .deb libnl-route-3-200_3.2.21-1_amd64 .deb
and the download address is https://launchpad.net/ubuntu/+source/libnl3/3.2.21-1/+build/5320735

For completeness sake a link to the bug for network-manager whose correction will help solving the problem when the respective update is published: Bug #1539634

Sorry for not replying earlies, as I was out of town.
There is no way to try these things you tell me, as I can't copy, paste nothing to a usb. But as I read in the bug you are refered to, others couldn't manage anything with a usb, too. I can't understand if the problem is solved, yet.

To verify whether you are really hit by this bug, open a terminal window and issue the command

dpkg -l | grep libnl

Which version number do you see, 3.2.21-1 or 3.2.21-1ubuntu1 ?

I see 3.2.21-1

I opened the terminal using the live cd. Is it ok?

no it's the second one. 3.2.21-1ubuntu1. That is that my computer gives me on the terminal, no live cd.

Ok, this confirms that you are hit by this bug.
Now let me try give instructions how to get your system back to a working network.

1. Boot your system normally from the hard disk (with broken network) and issue the command
uname -a
You will see some probably hard-to-understand detail information about the kernel running. The only important information is the last part. Is it i386 or is it amd64?

2. Boot your system with a live CD.

3. Insert an USB stick into the system.

4. If the information in step 1 was amd64, then browse to https://launchpad.net/ubuntu/+source/libnl3/3.2.21-1/+build/5320735 and download the files
libnl-3-200_3.2.21-1_amd64 .deb
libnl-genl-3-200_3.2.21-1_amd64 .deb
libnl-route-3-200_3.2.21-1_amd64 .deb
and save them on the USB stick.
Eject the USB stick (right click on the USB stick icon on the left and select eject)

5. Boot your system normally from the hard disk (with broken network)

6. insert the USB stick

7. open nautilus and identify the name of the USB stick (probably something like /media/1A2B-3C4D)

8. open a terminal window

9. Issue the command
cd /media/xxxx-xxxx
(replace xxxx-xxxx by the name of the USB stick identified in the previous step)

10. Issue the command
dpkg -i --force-downgrade libnl-3-200_3.2.21-1_amd64 .deb libnl-genl-3-200_3.2.21-1_amd64.deb libnl-route-3-200_3.2.21-1_amd64 .deb

11. reboot

XXXXX

If in step 1 you see i386 then you have to do replace two of the steps above:

4. If the information in step 1 was i386, then browse to https://launchpad.net/ubuntu/+source/libnl3/3.2.21-1/+build/5320738 and download the files
libnl-3-200_3.2.21-1_i386 .deb
libnl-genl-3-200_3.2.21-1_i386 .deb
libnl-route-3-200_3.2.21-1_i386 .deb
and save them on the USB stick.
Eject the USB stick (right click on the USB stick icon on the left and select eject)

and

10. Issue the command
dpkg -i --force-downgrade libnl-3-200_3.2.21-1_i386 .deb libnl-genl-3-200_3.2.21-1_i386.deb libnl-route-3-200_3.2.21-1_i386.deb

XXXXX

In case that anything is not yet clear to you, or if you get error messages, please do not hesitate to ask again.

By the way, you are hit by this bug, because you have enabled the trusty-proposed repository. The purpose of this repository is for testing changes and new software. Only people who are prepared to cope with problems should enable this repository.

Unfortunately this didn't work. I got:
dpkg: error: requested operation requires superuser privilege
I added sudo and then pasted the same and got:
dpkg: error processing archive libnl-3-200_3.2.21-1_amd64 (--install):
 cannot access archive: No such file or directory
dpkg: error processing archive .deb (--install):
 cannot access archive: No such file or directory
dpkg: error processing archive libnl-genl-3-200_3.2.21-1_amd64.deb (--install):
 cannot access archive: No such file or directory
dpkg: error processing archive libnl-route-3-200_3.2.21-1_amd64 (--install):
 cannot access archive: No such file or directory
dpkg: error processing archive .deb (--install):
 cannot access archive: No such file or directory
Errors were encountered while processing:
 libnl-3-200_3.2.21-1_amd64
 .deb
 libnl-genl-3-200_3.2.21-1_amd64.deb
 libnl-route-3-200_3.2.21-1_amd64
 .deb

Probably typo errors, there should not be a space character between amd64 and .deb

after the
cd /media/XXXX
(or whatever directory name) command, do you see the *.deb files when you execute the command
ls
?

And yes, sorry I forgot to write sudo for the dpkg command.

I tried again before seeing the above. Trying with the terminal I got:

dpkg: error processing archive libnl-3-200_3.2.21-1_amd64 (--install):
 cannot access archive: No such file or directory
dpkg: error processing archive .deb (--install):
 cannot access archive: No such file or directory
dpkg: warning: downgrading libnl-genl-3-200:amd64 from 3.2.21-1ubuntu1 to 3.2.21-1
(Reading database ... 286348 files and directories currently installed.)
Preparing to unpack libnl-genl-3-200_3.2.21-1_amd64.deb ...
Unpacking libnl-genl-3-200:amd64 (3.2.21-1) over (3.2.21-1ubuntu1) ...
dpkg: error processing archive libnl-route-3-200_3.2.21-1_amd64 (--install):
 cannot access archive: No such file or directory
dpkg: error processing archive .deb (--install):
 cannot access archive: No such file or directory
dpkg: dependency problems prevent configuration of libnl-genl-3-200:amd64:
 libnl-genl-3-200:amd64 depends on libnl-3-200 (= 3.2.21-1); however:
  Version of libnl-3-200:amd64 on system is 3.2.21-1ubuntu1.

dpkg: error processing package libnl-genl-3-200:amd64 (--install):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 libnl-3-200_3.2.21-1_amd64
 .deb
 libnl-route-3-200_3.2.21-1_amd64
 .deb
 libnl-genl-3-200:amd64

Still have to try the above with the space character between amd64 and .deb?

Thank you very much. This solved the problem. I also unchecked the trusty-proposed repository.
Thanks again!

Thanks Manfred Hampl, that solved my question.

affected by this bug
14.04 current am64

@Galen Thurber: YOU have already created a question document of your own https://answers.launchpad.net/ubuntu/+question/284402

What do you expect to get adding a "me too" to the already closed question document of somebody else?

On 16-02-04 12:52 PM, Manfred Hampl wrote:
> Question #284147 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/284147
>
> Manfred Hampl posted a new comment:
> @Galen Thurber: YOU have already created a question document of your own
> https://answers.launchpad.net/ubuntu/+question/284402
>
> What do you expect to get adding a "me too" to the already closed
> question document of somebody else?
>

because it contains a solution