OpenVPN over, discovering local devices

I would like to use OpenVPN to remotely connect to my local network, but also give me access to localized services when abroad.

So I manage to connect to the vpn over using the modifications proposed in this article. (just by manually editing /etc/openvpn/server/freedombox.conf)

By switching over my only ethernet interface to external firewall zone I can connect to the internet through it.
However I can’t connect to any other devices on my network. Pinging ip works but nothing else.

I can’t tell if this has to do with with section with the tun0 interface that’s popped up in my network configuration. But I can’t configure it in plinth. Do I need some rule for this device or is there another solution?

I believe that for this to work, local machine that you are trying to reach should have gateway set to FreedomBox machine or have a routing table entry that 10.91.0.* IPs could be reach via FreedomBox machine or should also be connected to FreedomBox via OpenVPN.

Would be tedious to modify each one though. for the moment I just use ssh -J to administrate them. but I would like to be able to use my printer and whatnot without having to go through that.

Is there some way for the freedombox to reroute everything that comes through the tunnel to it’s default interface? (or something like that I’m new to networking…)