安装Fail2ban

sudo apt-get update && sudo apt-get upgrade
sudo apt install fail2ban

启动服务

sudo systemctl start fail2ban
sudo systemctl enable fail2ban

默认设置

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

配置jail.local文件

sudo nano /etc/fail2ban/jail.local

[sshd]
enabled = true
port = ssh
logpath = %(sshd_log)s
backend = %(sshd_backend)s
banaction = iptables-multiport
maxretry = 3 #最大错误次数
findtime = 180 #多少时间内尝试（秒）
bantime = 900 #封禁时间（秒）
filter = sshd

重启fail2ban

systemctl restart fail2ban

查看日志

fail2ban-client status
fail2ban-client status sshd