NetworkManager not populating resolv.conf

Question

I recently upgraded from 11.10 to 12.04, and now NetworkManager isn't populating /etc/resolv.conf when connecting to wireless networks, when it had been working perfectly in 11.10. I'm not seeing any explicit errors in either the NetworkManager, UI or in syslog. How do I diagnose what's wrong?

Edit: If I try to run resolvconf, I get the error

resolvconf: Error: /etc/resolv.conf isn't a symlink, not doing anything.

What should it be, a symlink to and/or how do I get NetworkManager to populate it? This says the symlink should point to /run/resolvconf/resolv.conf, but that file does not exist on my system.

Solution 1

Use following command and answer YES to enable dynamic updates:

sudo dpkg-reconfigure resolvconf

Worked for me on Ubuntu 12.04.

Solution 2

I had the same problem. Seems that Ubuntu is using a local resolver now. The fastest way to remove that is to comment out the following line in /etc/NetworkManager/NetworkManager.conf:

#dns=dnsmasq

For more information, please take a look at this page.

Solution 3

If /etc/resolv.conf is a file then move it to /run/resolvconf/resolv.conf :

sudo mv /etc/resolv.conf /run/resolvconf/resolv.conf

Then create the symlink:

sudo ln -s ../run/resolvconf/resolv.conf /etc/resolv.conf

Solution 4

Had since a loooong time problems with my laptop, had to

sudo dhclient wlan0 

to be able to make the web work. Found that the resolv.conf was not updated by the network manager, and finally the

sudo dpkg-reconfigure resolvconf

solved my problem!

View more solutions

Comments

[Cerin]

Disabling that line and then restarting NM has no noticeable effect for me. The error still occurs and NM still refuses to populate resolv.conf.

[Mark D]

Worked perfectly. Have an old laptop with 12.04 a dead battery that I unplugged by accident. Could ping my home router but not get web pages. Oddly could access other wifi network. This gave me access through home network again.

[jdthood]

The question remains: Why was the symlink missing? This question is being addressed in bug #1000244 (bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/1000244). See comment #66 for my best guesses about the various causes of this problem.

[geekQ]

This helps. But easier and more reliable (typos) way for doing that is sudo dpkg-reconfigure resolvconf and answer YES.

[Chris Pfohl]

I wish there was a 'tip' or 'buy-me-a-beer' button on stack-exchange for thanking people.

[ErsatzRyan]

This is a great method if you're going to do dpkg-reconfigure resolvconf --frontend=noninteractive followed up resolvconf -u. If you don't move the file and symlink first, an unattended dpkg-reconfigure will fail because /etc/resolv.conf is not a symlink.

[Ethan Leroy]

Thanks for this information! I also had to restart the network manager: sudo /etc/init.d/network-manager restart.

[Reg Mem]

I needed to do this even on Ubuntu 16.04 / Elementary OS 0.4 Loki

[ASalazar]

This just happened to me on Ubuntu 16.10. The solution still works, although the dialog strongly suggests an immediate reboot. Edit: It happened out of the blue yesterday, more than a month after the upgrade.