This check port open tool is useful for checking port in your router is open or close. This is online security tool check port open or being blocked in your firewall system.
What are ports?
Ports are virtual pathways on which information on the Internet travel. There are 65,536 ports to choose from. A good analogy is to think of ports like extensions on a phone sytstem.
Ports 0 to 1023 - Well known port numbers. Only special companies like: MS SQL services (1433), Mail services POP3(110), IMAP(143), SMTP(25), Web services HTML(80).
Ports 1024 to 49151 - Registered ports; meaning they can be registered to specific protocols by software corporations.
Ports 49152 to 65536 - Dynamic or private ports; meaning that they can be used by just about anybody.
What is Port Forwarding?
Port Forwarding is a special function on the router, allowing transfer of data packets from the outside (from the Internet) to devices or computers on your local network (LAN). Usually the port on your router will be closed to prevent hackers on your system. But when you use the service to connect through port on the router you need to open it. For example: Yahoo! Messenger you need one of the following ports must be open: 5061, 443, 80.
The following is a list of common ports.
|20||FTP Data||File Transfer Protocol - File Transfer Protocol. Port for data.|
|21||FTP Control||File Transfer Protocol - File Transfer Protocol. Port for commands.|
|22||SSH||Secure SHell - "secure shell". Remote Management Protocol operating system.|
|23||telnet||TErminaL NETwork. Protocol implementation text interface over the network.|
|25||SMTP||Simple Mail Transfer Protocol - Simple Mail Transfer Protocol.|
|53||DNS||Domain Name System - Domain Name System.|
|80||HTTP / Web||HyperText Transfer Protocol - hypertext transfer protocol.|
|110||POP3||Post Office Protocol Version 3 - receive e-mail protocol, version 3|
|143||IMAP||Internet Message Access Protocol. Application-level protocol for accessing e-mail.|
|443||HTTPS||HyperText Transfer Protocol Secure) - protocol HTTP, which supports encryption.|
|445||SMB||Server Message Block. The remote access to files, printers, and network resources.|
|993||IMAP SSL||Protocol IMAP, supports SSL encryption.|
|995||POP3 SSL||POP3 protocol supports SSL encryption.|
|1433||MSSQL||Microsoft SQL Server - database management system. Port to access the database.|
|3306||MySQL||Access to MySQL databases.|
|5900||VNC||Virtual Network Computing - a system of remote access to the desktop computer.|
|5938||TeamViewer||TeamViewer - Remote control system for ensuring your computer and data exchange.|
|8080||HTTP / Web||Alternate port for the HTTP protocol. Sometimes used proxies.|