https://linuxconfig.org/how-to-configure-firewall-in-ubuntu-18-04
https://www.liquidweb.com/kb/install-configure-fail2ban-ubuntu-server-16-04/
Fail2ban:
fail2ban-client status
fail2ban-client status sshd
You should be able to do less /etc/sysconfig/iptables to get a listing of the rules. There's also iptables -L -n (to show addresses numerically--without -n it tries to look up the names of the addresses