OpenVPN client: Use to openvpn connection to office to access specific public IP

[fvnet]

Hello, I am in need for this specific scenario.
Our office has Public static IP and one of our overseas customer (who also has static IP)  has whitelisted ours so that we can connect to his server for the accounting ERP. Let's assume that our overseas customer IP is the: 88.777.666.55

When in office, employees can connect to his ERP just fine.
When our employees are teleworking, they use OpenVPN to connect to our office and its network. Where in OPNsense and the client can I configure that if the teleworking user needs to connect to 88.777.666.55 it should go thru the OpenVPN tunnel via our office?

Thank you so much in advance

[viragomann]

You have to add 88.777.666.55 to the "local networks" in the OpenVPN server settings. It requires CIDR notation, so add "88.777.666.55/32".

Also this requires an outbound NAT rule for the VPN tunnel network. Check if OPNsense has added a rule automatically. If not you have to switch the outbound NAT to hybrid mode and add it manually.

[fvnet]

Thank you so much. I was making the mistake and added it to the remote networks.
Could you comment on the NAT rule? All traffic from the VPN interface that are going to that ERP network is allowed (I can only add alias there)

[viragomann]

You have to add the outbound NAT rule to the WAN interfaces.