FreeBSD: Route jail traffic through VPN
I wanted to expose a single jail of my FreeBSD NAS to a network of a client via OpenVPN while it’s reachable both from my network and from the clients’ network. It should send all of its traffic through that VPN tunnel so that it appears like it is just another computer on that foreign network.
Luckily FreeBSD offers a great way to solve this by creating a separate routing table apart from my main routing table that is used when starting OpenVPN (so that it can populate it’s routes there) and when starting the jail (the jail in fact will consider that routing table as the only routing table available and therefore use it for anything).