Under Linux test using telnet port number is open

telnet 127.0.0.1 80
After the call, if prompted bash: telnet: command not found, then the following steps:

1, telnet check whether installed or not installed part;

telnet -qa * RPM
2, all lists all telnet installation package;

* List telnet yum 
3, telnet server installation

telnet-Server the install yum
. 4, telnet client installation

yum install telnet
At this point, the installation is successful, you can use telnet 127.0.0.1 80 Test port number is open