dns leak

[Adrian]

Using the network manager to set my OpenVPN I have a DNS leak after connecting to my secured network which also provides Internet connection.

I think solution is here: http://www.ubuntubuzz.com/2015/09/how-to-fix-openvpn-dns-leak-in-linux.html

However, I didn't find in the network manager windows any place to set those scripts.

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: network-manager-openvpn-gnome 1.2.6-2ubuntu1
ProcVersionSignature: Ubuntu 4.10.0-20.22-generic 4.10.8
Uname: Linux 4.10.0-20-generic x86_64
NonfreeKernelModules: openafs
ApportVersion: 2.20.4-0ubuntu4
Architecture: amd64
CurrentDesktop: Unity:Unity7
Date: Mon May 15 10:32:38 2017
InstallationDate: Installed on 2015-04-02 (773 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
SourcePackage: network-manager-openvpn
UpgradeStatus: Upgraded to zesty on 2017-04-18 (26 days ago)

[Vincent (dawansv)]

Adrian:

My understanding is that as of Ubuntu 16.10 (and this for 17.04 as well), DNS resolution is handled by systemd-resolved and not dnsmasq as in 16.04 and previous.

In earlier versions (using dnsmasq), when using openvpn directly from the console using a client configuration file, we had to use a script (called update-resolv-conf) to properly register the dns settings when connecting. I would assume that network-manager-openvpn runs a similar script for you in the background. The problem is that as of 16.10 and systemd-resolved that script does not play well with systemd-resolved, and therefore creates a leak.

Until network-manager-openvpn is updated to handle dns registration with systemd-resolved, you might need to revert to connecting to your vpn from the console (navigate to /etc/openvpn and calling sudo openvpn --config client.conf from the console). But first you need to create a client configuration file that has essentially the same info that you provide via the gui interface.

OpenVPN provides a sample file here:
https://github.com/OpenVPN/openvpn/blob/master/sample/sample-config-files/client.conf

Then to stop the dns leak you need to copy the update-systemd-resolved script to your /etc/openvpn directory and add a call to the update-systemd-resolved at the end of your client file. I explain this in this post:
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1624317/comments/42

Sorry if this is a bit technical, but hopefully you can get it to work.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.