Yet another ssh brute force attack and how to protect against it with iptables and sshguard

By chance, i looked into syslog ( /var/log/syslog ) and saw a ssh attempt to login from a ip outside local network. It was a brute force attack that started 7 days ago.. See down the post how to protect ssh from further attacks. Looking at the logs ( tail -n 200000 /var/log/syslog ) noticed