Ever wondered how to check open ports on IP address? In this article, we will reveal all the secrets and best techniques you need to know to master this art.
We live in a highly computerized world. Literally, every sector of industry uses some form of Information Technology (IT) so as to work. An important part of IT networks. This is where computers and devices are interconnected for the purpose of sharing information.
Thanks to networks, we can communicate with each other across borders. Computer devices are networked through ports. These are special channels through which your computer can reach the server which consequently gives it access to the Internet. How can you check open ports on IP address? Read on to find out.
The information that flows through ports is packaged as packets. There are many types of ports, for example, TCP and UDP ports. They can be open or closed in nature.
An open port is one which is actively configured to receive packets. On the other hand, a closed port is one which ignores or rejects all the packets that are directed towards it. A port can be closed through computer configuration or by the use of a firewall.
Check open ports on IP address
What is an IP address?
This is a term which is commonly used in Information Technology (IT) circles. An IP address is a unique identifier of every machine that is connected to a network. This could be a local intranet or the global Internet.
Packets of information are usually sent to this particular address. The flow of information to and from IP addresses is governed by the TCP/IP protocol. In addition to that, there are two types of IP addresses.
They include the IPv4 and IPv6 protocols. It is possible to check open ports on IP address in a computer. How is this done? Read on to learn more.
Port scanning
As indicated above, network ports are points on a machine which are designed for communication into and out of the Internet. Specific communication services normally listen in on a port. By doing this, they are able to receive data from a particular application connected to that port. After receipt, they can assess it and send a response back.
In the world of computer security, there are malicious elements that corrupt or masquerade as these services.
Once they do this, they can then access sensitive information or use viruses to destroy the computer system remotely. Hence, there are programs that have been developed to scan and test the ports on a computer system for the purpose of diagnosing if they are infected.
This is known as penetration testing. An example of a program that can check open ports on IP address is Nmap. In this form of port scanning, there are a number of parameters which are used.
Parameters of port scanning
The first parameter is the target. This is the particular IP address for which you want to test the ports. The ports to scan are also important parameters that are required in a session of penetration testing.
Network ports range from 1 to 65535. Hence, you can choose one or more ports to scan. After that, the next parameter is the service to scan for. Some ports have specific services attached to them.
For example ports 20 and 21 are used for the File Transfer Protocol (FTP) while port 80 is used for the Transfer Control Protocol (TCP). With these parameters set, specific commands can be sent to check open ports on IP address.
Local tool to check open ports on IP address:
Netstat: Netstat is a build in windows command line tool that can show you a list of current usage (open) ports on your system.
You run it from the command line, recommanded to run it as administrator, and execute the following command:
netstat -an
This command will list all the current open ports.
More on this tool can be found on our netstat post.
Open Port Viewer: Open Port Viewer a free tool for Windows 10 to list open port in windows, like netstat but with GUI. It supports IP v4 and V6 and it can resolve the remote IP to a domain name. read more and download on open port viewer tool page.
Portqry: An alternative method to check for open (listening) ports is the PortQry.exe Windows command.
It can be downloaded by visiting Microsoft Download’s Center and just like the TCPView command; it also runs as a standalone application.
Remote testing tools:
Nmap: Nmap (“Network Mapper”) is a free and open source utility for network discovery and security auditing. It is also commonly used by other systems and network administrator for inventory; monitoring service uptime or host and managing service upgrade schedules. The application runs on all best-known computer operating systems and is also available for Linux, Windows and Mac OS X in binary suites.
Advanced port scanner: An external tool that can be used is the Advanced Port Scanner It is a free network scanner allowing you to quickly find open ports on network computers and retrieve versions of programs running on the detected ports. The program has a user-friendly interface and rich functionality. is a free network scanner allowing you to quickly find open ports on network computers and retrieve versions of programs running on the detected ports. The program has a user-friendly interface and rich functionality.
Our port scanner: Want to dive deep into coding a basic port scanner, check out this article a windows port scanner. A basic command line port scanner tool that we developing for the Windows operating system. Using the c/c++ language.
Online port checkers:
This website is a free online tool that you can use to check if a port is open or not.
Conclusion
Port scanning is a very important part of network administration. It is used as part of the configuration and also for penetration testing. The facts above explore the activity of how to check open ports on IP address.