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:
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:
verb 4) and try again.
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. ↩