Enabling http access on port 80 for centos 6.3 from console

I would say your rule is at the end of your INPUT iptables list. Try this iptables -I INPUT 5 -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT and then run service iptables save. The A in your command appends the rule to the current INPUT list. This is after a rule that may have an explicit REJECT. The I in my command, places the rule in a line position, in this case line 5. Which should be BEFORE the default reject rule. Rules in IPTABLES work from top down and if a rule is match, the firewall applies the rule to the connection. I use this -iptables-rules-examples- really helpful

Command service iptables restart don't save your current iptables rules.

Execute service iptables save before restart it.