Simplest way to check if a particular port is open on the computing device
The reason I say computing device is because you may want to check if a particular port is open on a server, firewall, router, etc..
To check if the port is open simple use the telnet command. Open the command console and type in the command 'telnet <name / ip address> <port>'
To check if SSL port is open on EZref!nfo, type telnet ezref.info 443