Hey, is it possible to make VPN-channel redundancy, i.e. OpenVPN between two branches works now and for some unknown reason stops working, then its place is taken by, for example, l2tp or gre? I still have thoughts at the level of two or three vpn channels and ospf to configure, but somehow it seems to be a heavy load on microtiks will be.
Simply make different tunnels (eg. across different ISP) and have on top indeed a routing protocol take care of that.
Some of the tunnels will be mostly “idle” (except for some routing-protocol traffic across it) so it will not really impact your device.
IF your device is already struggling at this point of maintaining some extra tunnels, considering choosing something else…
Now this is WAN-side redundancy, you can also investigate to place 2 routers on these locations and using something like VRRP to offer some “LAN side” high availability in the bigger picture.