hello,
AFAIK ipsec VTI is usable in opnsense but there still seems to be a major open bug:
IPSec in transport mode between FreeBSD hosts blackholes TCP traffic
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242744
the corresponding opnsense issue has been closed due to inactivity 03-2020
https://github.com/opnsense/core/issues/3674
... only in transport mode? i think this happened to us in tunnel mode...
... shouldn't this bug be listed as known issue? or is there a workaround implemented in opnsense by now?
The bug can be reopened when we have a way to know what should be fixed. If the fix needs to be produced by FreeBSD there isn't much we can do also. We simply can't keep hundreds of tickets open where nothing happens for months due to any possible reason.
Cheers,
Franco