SIGUSR1[soft,ping-restart] received, client-instance restarting (OpenVPN Server)

[alexncs]

Dear all,

I have a problem with some of my OpenVPN site-to-site tunnels not working properly.
My set-up looks like this: I have a pfSense OpenVPN server that aggregates almost 30 site-to-site tunnels and the OpenVPN clients are configured on routerboards.  (I have 2.3.3-RELEASE-p1 version on my pfSense)

My problem is that 3 of these tunnels are being reset constantly, but at different period of times one from another. In each case I get these logs:

Inactivity timeout (--ping-restart), restarting
SIGUSR1[soft,ping-restart] received, client-instance restarting

I have a script on an equipment behind pfSense that is pinging constantly my routerboards via OpenVPN tunnels in order to check the communication, so there is a constant traffic via these tunnels. OpenVPN clients have the OpenVPN server IP configured as their NTP server, so they should be sync. Also my OpenVPN has the keep alive and the persist-tun configured.

keepalive 10 60
ping-timer-rem
persist-tun

After reading a bit about it, I still didn't find a solution or a concrete root cause for my problem. Let me know if you need any other info. I would very much appreciate your input on this matter.

Thank you and best regards,
Alex  :D