Set up IPsec site to site. Now Pfsense blocks all traffic to that FQDN



  • I had something really strange happen yesterday. I set up an IPsec site to site connection between  pfsense and a Sophos XG firewall at a remote location. This worked great until when after about 30 minutes the VPN link went down and I was unable to reach the XG itself (admin access via https) or any of the services behind it.

    pfsense appears to suddenly have decided to block everything going to that FQDN. Including the new VPN tunnel. No other traffic was affected. IPsec status showed as "connecting".

    After rolling back the pfsense VM to a point before I set up the IPsec connection everything is back to normal. But I would like to figure out what happened because I need the VPN.

    I am new to pfsense (first post, even) so bear with me.

    Why would the successful establisment of a  VPN tunnel break all communication with a FQDN?