Fail2ban installieren

sudo apt install fail2ban -y

Für EMail Benachrichtigung

sudo apt install sendmail -y

Eigene Konfigurationsdatein anlegen

sudo cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

sudo cp /etc/fail2ban/fail2ban.conf /etc/fail2ban/fail2ban.local

Fail2ban konfigurieren

sudo nano /etc/fail2ban/fail2ban.local

sudo nano /etc/fail2ban/jail.local

Eingestellte Werte für Default

[DEFAULT]
bantime  = 7d 
findtime  = 10m
maxretry = 3 
backend = auto

Eingestellte Werte für SSH

[sshd]
enabled = true
port = ssh
filter = sshd
logpath = /var/log/auth.log
maxretry = 3
bantime = 86400