Open Linux Port 80 (http)

# vi /etc/sysconfig/iptables
Append rule as follows rules on RHEL/CentOS version 5.x or older: -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
## Open 443 port i.e. HTTPS
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 443 -j ACCEPT
IF you are using RHEL/Centoa version 6.x or above, try: -A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
## Open 443 port i.e. HTTPS
-A INPUT -m state --state NEW -m tcp -p tcp --dport 443 -j ACCEPT
Save and close the file. Restart iptables service, enter: # /etc/init.d/iptables restart