Since none of the found instructions worked for me: here are my settings of my VPN tunnel into HAMNET. I’m currently using Fedora 36 on my main notebook and Fedora removed PPTP support back in Fedora 35—I could not get the PPTP tunnel working.

L2TP client

I found a document that shows the creation of an L2TP tunnel on MacOS and I used that as my starting point.

First of all, install NetworkManager-l2tp-gnome:

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$ sudo dnf install NetworkManager-l2tp-gnome

After that, create the new VPN tunnel in SettingsNetworkVPN.

Click the + button and select Layer 2 Tunneling Protocol (L2TP) and fill in the settings that you got from your Administrator (usually where you got your login data). I got mine from RWTH Aachen in Germany.

basic settings

Basic settings. Enter login data.

IPv4 settings

IPv4 settings. Those work for my setup at home.

IPv6 settings

I'm not using IPv6 at home...

IPSec settings

Somehow that setup only worked when I removed this setting?#*!

PPP settings

And I ended up using those settings for PPP

More information

I’ve also found some more links—just when I finished formatting this article.

It looks like the following article is online since 2018; but I found this after I started using the L2TP tunnel that I just created a few hours before. It describes the setup of an OpenVPN client, but it is limited to users with a static HAMNET IP address.