VPN Tunnel Between Opensense and On-Prem Firewall disconnects Periodically

[m.crameri@dpstudio.ch]

Good morning,

I have set up a VPN tunnel between my OpnSense VM on Azure and the on-premises network. The site-to-site connection is working, and I can communicate between the two networks, but it disconnects after less than an hour.

At that point, I have to manually restart the tunnel from both the OPNSense and Sophos firewalls, after which it works again for another hour before the issue repeats.

Do you know if there's a setting in OPNSense that could resolve this?

Thank you.