OpenVPN Server should listen to IPv4 & IPv6

[Adrian0]

Hello,

I've a setup with a working OpenVPN Server on pfSense. There are several IPs on my WAN interface and I want to bind the Server to a specific one. That works if I use IPv4 OR v6, but when I select both protocols, it in only possible to bind it to all available addresses. Thats bad because I can't create a second instance on the same port.

Is there any possibility to create one OpenVPN server instance and bind it to one v4 and one v6 address?

What I did so far:
As workaround I use two OpenVPN Server instances. One for v4 and another one for v6. It is working, but a little nightmare to maintain. You need tunnel subnets for each instance and this affects firewall rules. Terrible.

[kiokoman]

it's an openvpn server limitation.
https://community.openvpn.net/openvpn/ticket/556

summary:
it's on our radar since quite a while, but "complicated"
there wasn't much traction, development is currently on halt, But I'd like to resume it at some point.

[Adrian0]

Wow, this "feature wish" was opened 5 (five) years ago. I would call it bug fix. So sad that dual stack is not understood as default for any node.

Thanks kiokoman for the link.