Port Knocking for VPN?

[Bamsefar]

Under OpenVPN server, Advanced settings, there is a Firewall parameter. Normally this is "Auto" - however anyone know how "External" and "Custom" works?

My idea is to get a port knocking set up with IPTABLES, like this one:
https://www.digitalocean.com/commun...knocking-using-only-iptables-on-an-ubuntu-vps

Best, of course, would be if this would be included as an option within the firmware. However I fully understand and respects RMerlins choice of not extending any more functionality into the firmware. So that is why I wonder what "External" and "Custom" is for?

 

[A.D.]

My idea is to get a port knocking set up with IPTABLES

I'm a port knocking fan and I can't understand why it's so rarely used.

Maybe one reason is that there doesn't seem to be a generator tool (which would also have to be the foundation of any UI based approach).

I'd try it on the command line, not in the UI. I was experimenting with isolating guest WLANs by discarding packets in ebtables / iptables and it seemed to work well (although I didn't finish it and the artefacts I found here in the forums are pretty wrong at least regarding my requirements). You can just have the commands run at startup as documented elsewhere.