I have 3 firewalls. On one, I have multiple OpenVPN servers running, no issues. On another, single OpenVPN instance running, no issues. On the third, I can't seem to get it to work.
I keep seeing Could not determine IPv4/IPv6 protocol. Using AF_INET and TLS handshake errors in the OpenVPN logs. On the dashboard of the firewall, under OpenVPN clients widget, I see the public IP of the location I'm trying to connect -from-, and no virtual IP.
I've compared the server settings with the other 2 firewalls and can't find a difference. I've also deleted and recreated the CA, INT CA, Server and client certificates a handful of times now, and verified the associated firewall rules are identical for allowing the connection across all 3 firewalls.
Struggling to figure out why it works on the other two OPNSense firewalls but not this one.
Did some more testing and found something interesting.
At one site, I can connect to OpenVPN fine from my desktop. There's a wireguard tunnel between my site and this site.
At the site that isn't working, there is also a wireguard tunnel, setup the same way, same allowed IP configuration meaning I'm just allowing the entire /24 network in the tunnel. I can't connect to the OpenVPN at that site from my desktop.
The interesting part, is if I RDP to a machine on a different VLAN, the OpenVPN connection works fine. Thoroughly confused.