fail2ban is installed on every launched instance at boot. The default number of login failures is set to three. If you want to change that, you can:
sudo nano jail.local
and look for this section.
enabled = true
filter = sshd
action = iptables[name=SSH, port=22, protocol=tcp]
sendmail-whois[name=SSH, dest=root@localhost, sender=Fail2Ban, sendername="Fail2Ban"]
logpath = /var/log/secure
maxretry = 3
Change the maxretry value and save the file.
sudo systemctl restart fail2ban
to restart the service with the new config.
To remove any banned IPs you can get the instructions from http://wiki.jetstream-cloud.org/Troubleshooting+-+FAQ
sudo iptables -L -n
Look for your IP number in that output, if it's there, proceed
sudo fail2ban-client status
Should show you fail2ban is working and your jail name(s):
[js-157-95] root ~-->fail2ban-client status
|- Number of jail: 1
`- Jail list: ssh-iptables
sudo fail2ban-client set ssh-iptables unbanip YOUR_IP_NUMBER