I would like to restrict access to the SSH port of a new CentOS 6.2 server to select IP addresses but the Firewall GUI utility seems to be an all-or-nothing scenario. Either the port is firewalled or it is opened.
If I make changes using the IPTABLES commands and save them out, and then later someone uses the Firewall GUI to make other modifications such as opening up access to FTP or the like, will that remove the changes I made using the IPTABLES commands or manual edits to the tables?