ufw broken on Linux Mint 17.3
on my Linux Mint 17.3 x64 Cinnamon, ufw appears to be broken (0.34~rc-0ubuntu2).
Networking seemed to work alright, surfing was no problem, also FTP and SSH worked. But not Bonjour, which I need to use the scanner that is inside my Canon MX925. So I used gufw (14.04.
Looking deeper inside the matter, I realised that the default inbound policy is deny. So surfing should not be possible, but it works alright.
sudo ufw status verbose
Protokollierung: on (medium)
Voreinstellung: reject (eingehend), allow (abgehend), disabled (gesendet)
Neue Profile: skip
Zu Aktion Von
-- ------ ---
8612 ALLOW IN Anywhere (log)
5353 ALLOW IN Anywhere (log)
8612 (v6) ALLOW IN Anywhere (v6) (log)
5353 (v6) ALLOW IN Anywhere (v6) (log)
8610 ALLOW OUT Anywhere (log)
8612 ALLOW OUT Anywhere (log)
8610 (v6) ALLOW OUT Anywhere (v6) (log)
8612 (v6) ALLOW OUT Anywhere (v6) (log)
Bonjour should be the only thing working, but in fact, it's the only thing NOT working. So I looked at those predefined sets of rules that ufw should come with, according to
but most of the ones mentioned there are missing.
sudo ufw app list
Only CUPS and Samba are known? Not even DNS or tcp/80 ? Since surfing works alright, my guess is that ufw does not really work together with iptables, which to my understanding is the "real firewall" that (g)ufw is only a frontend for. So ufw does not show all rules that are in force, and ufw does not correctly apply new rules at the correct position in the chain, so they get defeated by the existing rules, thus Bonjour gets broken.
Dec 15 14:00:30 FSC-neu kernel: [72537.358551] [UFW BLOCK] IN=eth0 OUT= MAC=90: