Installing an up-to-date Fail2Ban (Debian/Ubuntu)

The F2B version available via apt for Debian/Ubuntu is old and does not support IP6 (as at the time of this document being written). So let's grab a newer version from the source at github.

Note: Only versions 0.10+ offer IP6 support.

Switch to your home directory or somewhere you can work with downloaded files.

Get the latest version of Fail2Ban, switch to the created directory and install it using the python installer script.

# get latest fail2ban version
git clone https://github.com/fail2ban/fail2ban.git
# change to the newly created directory containing f2b
cd fail2ban
# run the installer
sudo python setup.py install

Let's test the installation by running fail2ban-client. If it displays the help screen, then things are probably set up properly.
```
fail2ban-client -h
```

Now, let's configure systemd to load fail2ban automatically on system start-up.

# copy the service file to the correct location
sudo cp files/debian-initd /etc/init.d/fail2ban
# tell systemd to refresh itself to recognize the new service
sudo update-rc.d fail2ban defaults

Let's go ahead and start the service to make sure it doesn't run into any problems. You should not see any errors reported and should have a pleasant 'green dot' showing up.

--full --no-pager means display everything and wrap output so it isn't cut off and we can actually read it!

# start the service
sudo systemctl start fail2ban.service
# check it's status for any errors
sudo systemctl --full --no-pager status fail2ban.service

One more test just to be sure everything is set up. You should see f2b report it's version without any errors being generated.
```
fail2ban-client version
```

That's it! Fail2Ban is set up and running on your system. Now we have to apply our configuration.