Change the Default SSH Port:

• Edit /etc/ssh/sshd_config and set a new port:

  Port 2222

• Restart SSH: sudo systemctl restart sshd

Disable Root Login:

• In /etc/ssh/sshd_config, set:

  PermitRootLogin no

Use SSH Keys for Authentication:

• Generate a key pair on the client:

  ssh-keygen -t rsa -b 4096

• Copy the public key to the server:

  ssh-copy-id user@hostname

Limit Access by IP:

• Use /etc/hosts.allow and /etc/hosts.deny to restrict SSH access.