Fail2ban failed on Debian 12 - solved

[j323m13]

On Debian 12, fail2ban needs a bit more configuration to start. Without the service will crash.
If you run the following command:

systemctl status fail2ban.service

you get:

× fail2ban.service - Fail2Ban Service
Loaded: loaded (/lib/systemd/system/fail2ban.service; enabled; preset: enabled)
Active: failed (Result: exit-code) since Fri 2024-03-15 18:43:15 CET; 6min ago
Duration: 92ms
Docs: man:fail2ban(1)
Process: 3294 ExecStart=/usr/bin/fail2ban-server -xf start (code=exited, status=255/EXCEPTION)
Main PID: 3294 (code=exited, status=255/EXCEPTION)
CPU: 78ms

Solution:
In the file:

/etc/fail2ban/jail.local

add:

[sshd]
backend=systemd
enabled = true

then restart the server or fail2ban. Run the command systemctl status fail2ban.service

fail2ban.service - Fail2Ban Service
Loaded: loaded (/lib/systemd/system/fail2ban.service; enabled; preset: enabled)
Active: active (running) since Fri 2024-03-15 18:54:33 CET; 1min 29s ago
Docs: man:fail2ban(1)
Main PID: 530 (fail2ban-server)
Tasks: 5 (limit: 2315)
Memory: 52.3M
CPU: 509ms
CGroup: /system.slice/fail2ban.service
└─530 /usr/bin/python3 /usr/bin/fail2ban-server -xf start

Problem solved.

[DiMMMMM0N]

I did everything according to the instructions, but the error remains. Debian 12