[Solved] - GUFW - 2 questions.

[kdemeoz]

Hello

One of the first things i do after installing any distro is to install GUFW if not already present, then turn it on... accepting its default settings. Just now on my Tower i opened GUFW to check something, & was shocked, really shocked, to see that it was Off. I cannot grasp how this is possible, & i felt horrified.

1. What if any circumstances can arise that would deactivate GUFW? Can any of the causes be malicious? Can a system crash / freeze do this? Is there any way i can create some kind of automatic infallible screen alert if ever GUFW is inactive?

2. To what extent might my Tower have been vulnerable / compromised [given that i used to regard GUFW as "set & forget", i have not checked it for possibly several months, & so now i feel quite anxious about the implications of this shock discovery]?

Thanks.

[kdemeoz]

Well, whilst my #1 remains a mystery to me, it seems that my #2 might have been an unnecessary exercise in worrying over nothing. I just used Steve Gibson's Shields Up site test https://www.grc.com/x/ne.dll?bh0bkyd2, firstly with GUFW off, then again with it back on. It seems that my Tower was no less protected either way [which now makes me wonder about the point of using GUFW?]:

   

   

[leszek]

Every Linux Distro ships with an active ip filter (also called personal firewall) known as iptables.
Ufw and it's graphical gufw are just simpler user interfaces for iptables.
By default all ports are closed if you not start an application which opens up a port (ssh server or Webserver, smb server and so on)

[kdemeoz]

Excellent, that retrospectively makes sense, thank you. If i understand you correctly, though i still have no explanation of the root cause for my GUFW having turned itself off, or being turned off by some unknown process (i did not do it], it would appear that overall, this is a totally unimportant occurrence, re security...?

[leszek]

Yeah exactly. I am not really sure what gufw does when enabled and disabled.
Maybe only activating custom user filtering. So if you have setup some rules it applies them.

[kdemeoz]

Thanks again. I have now learned another new, good, thing. Marked as Solved now.