How to setup L2TP VPN on Ubuntu 20.04

L2TP/IPsec on Ubuntu is one of those things that should be easy. The UI is there, the docs say “fill these fields and connect”… and then you hit a timeout and start questioning your life choices.

This guide walks through a setup that actually works on Ubuntu (20.04 and newer), plus fixes for the most common ways it fails (timeouts, EAP errors, and authentication problems).

L2TP (Layer 2 Tunneling Protocol) is a VPN method that creates a tunnel between your device and a VPN server, and IPsec adds encryption to keep that tunnel secure.

Install the L2TP NetworkManager plugin

NetworkManager-l2tp is the most painless way on desktop Ubuntu. It’s a VPN plugin that supports L2TP and L2TP/IPsec through NetworkManager:

sudo add-apt-repository ppa:nm-l2tp/network-manager-l2tp
sudo apt update
sudo apt install network-manager-l2tp network-manager-l2tp-gnome

At the time of writing, it was 1.20.4, useful resource is github repo - https://github.com/nm-l2tp/NetworkManager-l2tp. I suggest you go through reported issues and Wiki for Known Issues.

Go to Settings -> Network -> VPN -> Click a + sign -> L2TP:

Type your gateway ip, username and password:

Click on IPsec Settings and type your pre-shared key, don't fill anything in Advanced, just click Apply, and Apply again.

As far as documentation I saw, that would be enough for connecting to the VPN. But nope, my VPN was constantly timeouting.

Create the VPN connection (GUI)

Figuring out what went wrong, that was a pain.

I scanned the logs in syslog and journalctl -f , found an error like "EAP: unknown authentication type".

If you get a similar error, solution would be to go to your VPN settings, then PPP settings, disable all authentication methods except one, like MSCHAP.