It addresses this issue in the documentation, says it was upgraded from Static Routes requiring multiple public IP’s for each VPN on the server-side to the new Net-balancer way of doing things…
“VPN LAN-to-LAN that may be configured in Zeroshell may be obtained using OpenVPN and TAP virtual interfaces. The latter entirely resemble real Ethernet interfaces and, as such, they may be aggregated through Bonding. This feature has been available since the first release of Zeroshell. However, for VPN bonding to be justified, each VPN tunnel belonging to the bond must flow to a separate Internet link. Before Net Balancer was introduced, this was done through static routes which required at least one peer to have two public IP’s. Now, thanks to Net Balancer, the VPN site-to-site configuration form allows you to choose a gateway to set up the ciphered connection. This greatly simplifies configuration by no longer requiring static routes and two public IP addresses.”
It must be something small we’re missing….
I did notice in Windows when I change the gateway’s interface to use before clicking save it resets it back to
and when I return to change the gateways settings it doesn’t remember the interface I had previiously selected.