OpenVPN: Session invalidated: KEEPALIVE_TIMEOUT

[bazbaz]

Hi,
I have a road warrior OpenVPN tunnel. Authentication is based on local users + user certificates.

Connections are ok and work, but every 45 seconds the connection goes down and OpenVPN Client reconnect it. Its log says "Session invalidated: KEEPALIVE_TIMEOUT"

I cannot find how it tries to perform a keepalive and where the problem can be, any idea?
thanks

[bartjsmit]

RTFM? :) https://openvpn.net/community-resources/reference-manual-for-openvpn-2-5/ search for keepalive

[bazbaz]

Ok, I see, but still I cannot find an idea about the problem. The VPN is working well, so traffic is ok. What kind of keepalive is the problem? The client can ping OPNSense on the IP address assigned on the tunnel (the first of the subnet). The firewall also does not log any dropped packed.
Is there some setting in my opnsense I miss? I' have many other OpnSense working well with OpenVPN DU and this is the first time I see this problem.

[bartjsmit]

Increase the verbosity of an OpenVPN client, or run it in the foreground. You should see the keepalive packets going back and forth.

[bazbaz]

nothing useful

I solved enabling keepalive frequency and timeout on opnsense side, that were emtpy.

[LozBoz]

Would you be more specific and say how enabling keepalive frequency and timeout was done on the opnsense side?

I think I'm having a similar issue.

[bazbaz]

sorry, I don't remember the exact settings. I suspect in openvpn server main settings