I switched from Mac to Linux recently and a thing I got stuck on for a while is the easy way to establish L2TP VPN connections from a mac to a Meraki firewall. On a mac it is very easy to set up, but on Linux I ran into some trouble getting it working. Now that is does work I'd thought I'd share a solution. Please note that this is a bit static and may break if future meraki updates changes cipher suite for example.
Ofcourse everything Linux-related is distro-depending so this is tested on Debian 10, kernel 4.19, i3wm, since that is what I use. The firewall is a Meraki MX64.
1. Make sure network-manager is handling network connections. Read this.
2. You need the following packets (depending on WM):
network-manager-l2tp-gnome network-manager-strongswan network-manager-l2tp strongswan-nm
3. Restart network-manager
systemd restart network-manager
4. There is a daemon running called xl2tpd that messes up things. There's info about this on this forum. So:
sudo systemd stop xl2tpd
sudo systemd disable xl2tpd
5. Create a VPN connection in nm-connection-editor and modify IPSec and PPP properties accordingly:
Cheers!