I am trying to setup a site-to-site VPN between Vyos 1.3.0 and pfSense/OpnSense.
The problem is the tunnel comes up but I cannot have traffic from the pfSense/OpnSense site to the Vyos site until I first send a ping from the Vyos site to the pfSense/OpnSense site.
Both sites are on public IP addresses, no NAT inbetween. I have tried different combination of the connection-type parameter respond/initiate but nothing worked.
OpnSense is based on freebsd 13.0 and pfSense on FreeBsd 12.3. Both behave similair.
Any idear how to troubleshoot this?