Securing Ubuntu SSH

1. Update the /etc/ssh/sshd_config file to have the following added:

   PermitRootLogin no

2. Install fail2ban using the following command:

   sudo apt-get install fail2ban

3. Create the file /etc/fail2ban/jail.d/jail-debian.local file to have the following:

   [sshd]
    enabled = true
    port = ssh
    filter = sshd
    logpath = /var/log/auth.log
    maxretry = 6
    bantime = -1
   

4. Restart the service using the following command:

   sudo service fail2ban restart

See Unbanning an IP