To open port 22, open a terminal, switch to root and run the following command:
iptables -A INPUT -p tcp -m tcp --syn --dport 22 -j ACCEPT
Hit enter end exit your shell
Two good sources for configuring and managing iptables are:
Although I am sure that there is some sort of GUI to manage iptables, it really will help you in the long term if you learn how to manage and monitor your firewall from the command line.
---------- Post added at 05:04 PM ---------- Previous post was at 04:46 PM ----------
I forgot to mention, if you want to keep this port open for future use, do the following to make the changes permanent:
iptables-save > /etc/sysconfig/iptables
systemctl restart iptables.service
Just remember, always start your security at "Paranoid" and RAISE
your security as needed. I am not trying to be funny. Leaving ports open that do not need to be open is a bad security practice to get into.