Opening firewall ports on a linux machine

To open any port on a linux machines with iptables install you can follow these easy steps.

vi /etc/sysconfig/iptables

press insert to add more ports like for 110 port
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 110 -j ACCEPT

once done type
:qw

Restart iptables
/etc/init.d/iptables restart