Comment 3 for bug 1650489

Sorry, corrrection:
That should have read "b) ufw ignores rules that completely open up incoming traffic from a specified port"

I have added a rule that everything coming from port 8612 shall be allowed. So no matter ufw recognises that state of the communication from the PC to the printer or not, _everyhing_ that the printer sends from its port 8612 must be allowed. But it does get blocked...

This
Dec 17 16:56:09 FSC-neu kernel: [255876.937195] [UFW BLOCK] IN=eth0 OUT= MAC=90:1b:0e:18:56:e3:60:12:8b:46:ce:55:08:00 SRC=192.168.1.251 DST=192.168.1.31 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=26547 PROTO=UDP SPT=8612 DPT=59438 LEN=40
should never happen, regardless of ufw's states...

sudo ufw status:
Zu Aktion Von
-- ------ ---
8612 ALLOW Anywhere (log)