Open specified port under Linux

Today, the Linux test server restarted the results caused by the Web site can not open, IP will be able to ping the Apache restart success, Telnet to the next 80 port results are not connected, this should be outside the network 80 was blocked by the firewall behind the 80 port development under the following can be, the steps are as follows:

1, modify the Vi/etc/sysconfig/iptables file, add the following line:

-A rh-firewall-1-input-m state--state new-m tcp-p TCP--dport ports to open-j ACCEPT

2. Restart Iptables
Command: Service iptables restart

Whether the query port is open:

Netstat-an | grep Port

Open specified port under Linux