I have an IPSEC connection between two OPNSense firewalls. This connection is configured using IPv6 addresses.
This worked OK between OPNSense 26.4 business and OPNSense 26.1. After upgrading to OPNSense 26.7, large packages are not passing the IPSEC tunnel.
On 26.1, a ping -s 1500 passes the tunnel ok.
On 26.7, ping -s 1500 stopped working. A lower length (-s 1400) still works ok.
An analysis shows, that the 26.7 doesn't send anything to its IPV6 peer.
Switching the IPSEC connection to IPv4 solves the problem.
Looks like a regression on 26.7.
Best regards, Jochen
I just found https://forum.opnsense.org/index.php?topic=52410.0
This might be related.
Best regards, Jochen