OpenPort.net – Question And Answer Page:

In this page we will try to answer common question that people ask in subjects that relevant to open port.

List of Terms:

  • IP – IP stand for Internet Protocol, a number that is use to identify device address over the internet.
  • TCP – TCP stand for Transmission Control Protocol, a reliable protocol to communicate between devices over the network, one of the core protocols.
  • UDP – UDP stand for User Datagram Protocol, a protocol that use to communicate between devices over the network, without error checking, and there is no guarantee that the data will arrive and in What order.
  • Domain Name – Domain name is an easy to use, human friendly name of a site.
  • WWW – WWW stand for World Wide Web, it use as prefix to the domain name.
  • HTTP – HTTP stand for Hypertext Transfer Protocol, used to exchange or transfer hypertext.
  • HTTPS – HTTPS stand for Hypertext Transfer Protocol Secure, transfer hypertext data on a secure, SSL, protocol.
  • SSL – SSL stand for Secure Sockets Layer, use to transfer data in crypt way.
  • Port – Port is a number from 1 to 65535 that use by software to identify an entrance to the application.
  • Open Port – Open Port is a port that current use by an application and due to that it is open.
  • Open Port Checker – Open Port Checker is a tool to check if a port number is currently open or closed.
  • Online Open Port Checker – An Online Port Checker is an online tool that check if port is open or closed.

For all the above question you can navigate to Wikipedia web site.

Question And Answer:


IIS open port – IIS, like other web servers, use the default port 80 for HTTP traffic and 443 for secure HTTP traffic – HTTPS


Netstat not showing all open ports:

In most cases this issue can be cause due to lake of privilege. You need to run the command with an account that have the administrator privilege.

You can use this script:

  1. Create an empty text file.
  2. Add the following lines to the text file:
    netstat -nab
  3. Save the file as run.bat
  4. Right click on the file and select – run as administrator.
  5. The output you see is a list of all the open ports.
  6. Hope it helps.
  7. Command line open port 53 – You can use the command line ‘netstat -nab’ under windows to check if port 53 is open.


I want to open port X,Y and Z:

Ok, for a port to be open we need something to listen to that port. RE: A service that use this port. Now you also need to open the ports in your local firewall. If you are after a router you also need to configure your router to forward the connection on the ports. I am sure you can find some video guide on how to do it on YouTube .


Is the port open if the port state shows established:

Yes, this mean that your computer and the other computer are connected, this is why it mark as established.