We have RHEL 5.X in our production setup. It is recommended to block unused ports in a RHEL system using iptables. The port range in very large from 1025-65535 as 0-1024 is reserved for the system. At any time, there could be like 100-200 open ports only so that would mean like blocking ports in thousands which are not used as the available port range is around 64K. Would request your inputs on this of how to block unused ports.
I hope my question is clear of how to block unused ports.
Requesting a reply to my query.
Regards