Any OpenVPN Server needs an open port forwarded to the correct server IP address to function. Many times this is not possible because of firewall restrictions. This is where “reverse VPN” comes in handy.
The other application of “Reverse VPN” is multi site connections. With “reverse VPN” many remote locations can be connected to form one effective LAN.
Set up routers as per “Site to Site” How-to
Each client(s) must be setup correctly
The really important part is “Subnet behind client”. This is the LAN where the client is being placed.
If “No Subnet Defined” is selected you will effectively have a one way connection e.g. Client to server