How to Block Brute Force Attacks

1. Use Fail2ban

sudo fail2ban-client status sshd

2. Set Up SSH Rate Limiting with UFW

sudo ufw limit ssh/tcp

3. Use iptables Recent Module

sudo iptables -A INPUT -p tcp --dport 22 -m conntrack --ctstate NEW -m recent --set
sudo iptables -A INPUT -p tcp --dport 22 -m conntrack --ctstate NEW -m recent --update --seconds 60 --hitcount 4 -j DROP

4. Change SSH Port (Recommended)

sudo nano /etc/ssh/sshd_config
Port 2222