CentOS - Webserver Configuration

Check httpd service
#service httpd status

Start httpd service
#service httpd start

Set to AllowOverride All
#nano /etc/httpd/conf/httpd.conf

From :
Options FollowSymLinks
AllowOverride None

To :
Options FollowSymLinks
AllowOverride All

Add iptables rule for port 80 (http)
#iptables -I INPUT 5 -i eth0 -p tcp --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT

Check iptables rule
#iptables -L INPUT --line-numbers

Example output :
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
2 ACCEPT icmp -- anywhere anywhere
3 ACCEPT all -- anywhere anywhere
4 ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:ssh
5 ACCEPT tcp -- anywhere anywhere tcp dpt:http state NEW,ESTABLISHED
6 REJECT all -- anywhere anywhere reject-with icmp-host-prohibited

Save iptables rule
#service iptables save

To ensure that httpd start every time system restarted
#chkconfig httpd on

iptables rule successfully added in line 5, so we should have access to apache webserver page.

So if you would like to delete second rule :
#iptables -D INPUT 2