Question: Normally `ufw` is disabled after a fresh setup. Recently I saw, ufw is activated. 
If I type `sudo ufw status verbose` the output is

```
status:activ
protocol: on (low)

```

But `/var/log/ufw.log` is empty. Someone knows why? Any hint is welcome.

Answer: 
```
sudo ufw status verbose

```

to check if you are logging. If you are not you enable logging with ...

```
sudo ufw logging on

```

In case this does not start creating log files check with

```
sudo service rsyslog status

```

if rsyslog is running and if so do a 

```
grep -i ufw /var/log/syslog
grep -i ufw /var/log/messages
grep -i ufw /var/log/kern.log

```

and check for errors regarding ufw (and act upon them ;) )
The following worked for me (running a Raspbian 10 Pi, but it's the same in Ubuntu).

Enable medium logging:

```
sudo ufw logging medium

```

Try to generate some traffic from the Linux machine.
Then check if you have a log:

```
sudo find /var |grep ufw.log

```

To follow the log in real time:

```
tail -f /var/log/ufw.log

```

And to set the logging to "low" for less logging:

```
sudo ufw logging low

```

The "low" setting logs all blocked packets not matching the defined policy, as well as packets matching logged rules.