Roland Ewald

Software Engineer · Researcher

OpenVPN, Ubuntu 16.04, and WiFi connection problems


I spent quite some time over the last few weeks to debug a strange issue that happened when connecting to a (newly configured) OpenVPN server with Ubuntu 16.04. Every few minutes the VPN connection simply dropped, with this log message:

Inactivity timeout (--ping-restart), restarting

The problem occurred sporadically, and nothing (firmware update on router, ‘polling’ a server inside the private network to generate traffic, RTFM, etc.) helped.

Yesterday I finally found a workaround in this AskUbuntu answer for a similar connection problem: after editing the WiFi connection and setting the IPv6 settings to Ignore, everything seems to work fine (for now). Since there are other workarounds for problems with the same symptoms, I suggest trying this first, since it is a simple and quick workaround.

OpenVPN support on Ubuntu can be rather challenging1 to set up, depending on the server configuration.

Here is what I learned about that in the last weeks:

  • Depending on your configuration file, import into the Ubuntu network manager may not work, so you should check if there is a known bug that affects you, e.g. missing support for certain OpenVPN options.

  • Even when you got the import working, the network manager may simply not support all settings you need. In this case, you will have to run OpenVPN manually: sudo openvpn path/to/my/config.ovpn (this is also useful for debugging).

  • Some issues are caused by multiple machines being connected to the same OpenVPN server with the same certificate. Only use a single session to rule out any problems in that regard.

  • WiFi can cause a lot of trouble for OpenVPN and you may not notice very brief connection interruptions yourself, so improve your router configuration if you suspect this to be a problem (e.g. switch off the 5GHz band, only use 802.11b+g, etc.).

  • DNS setup also needs an extra step that may be missing from your OpenVPN config file. It should contain:

script-security 2
up /etc/openvpn/update-resolv-conf
down /etc/openvpn/update-resolv-conf
  • For more troubleshooting, change the verbosity level in your config file (e.g. to verb 4) and try again.

Good luck!

  1. When I configured my clients for the previous VPN setup, it was the other way around: a nightmare on Windows, but a piece of cake on Ubuntu. I guess it really does depend on the specific OpenVPN setup.