Environment: CentOS 6.5, nginx 1.5.9
Problem: Nginx is installed through yum but does not show index.html(the first page) in the web browser.
Reason of the problem: The problem was the firewall. You can check it from /etc/sysconfig/iptables. Refer to the following solution.
Append -A INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT
sudo service iptables restart