NPF (mis?)behaviour vs. distant site (mis?)behaviour ...

[Anthony Mallet <anthony.mallet%laas.fr@localhost>]

On Wednesday  4 Oct 2023, at 23:07, Anthony Mallet wrote:
> Same #2 bare ACK, but this time the RST packet seems to be swallowed,
> neither passed nor blocked (all my block rules have a "log"
> procedure). Is this a NPF bug?

After a bit of search, I guess I'm in that exact situation :
https://serverfault.com/questions/733681/server-sends-ack-in-response-to-syn-causing-a-reset-in-tcp-request-from-the-clie

So, regarding NPF, it seems that because the ACK is not considered
part of the current stateful connection, it is dropped. And the RST
is never sent. Does that sound correct?