I have a router with OpenWRT in use at 5 different customers.
The routers are each behind the router of the ISP. At the routers of the ISP I can‘t modify anything.
(Like port forwarding ...)
Now I want to create on all 5 routers a VPN client, which connect to a public, hostet from me VPN server (Linux).
I would like to be able then to manage them remotely from my network at home.
However, the routers should not route all normal traffic via the VPN connection, but only if I connect to them.
Has anyone ever built something like that?