A port is a virtual address on a person’s computer or on a network device that authorizes it to connect with any other devices over the network, and open port checkers are tools that you can use to check what ports are open in case of security needs or if you have connection problems.
Ports are also known as endpoints between two connections. If a certain program wants to work with a certain network, it will automatically open the port with a unique number. This will enable the port to work with remote clients or servers.
Nowadays, more and more applications can only be found online so there is no need for unnecessary installations.
Of course, there are a wide range of methods to check your open ports from a certain IP, but most of them require some steps that need to be memorized first in order to work.
They may also need certain 3rd party applications that also need to be installed on your computer in order to identify them.
Each game or application uses different ports, so you will have to check for the correct ports to open.
Online open port checkers:
One of the most comfortable solution to this issue is the usage of an online port check tool, which is usually user-friendly and really easy to understand how it works.
Most of these open port checkers require the user to type in his/her IP address in order to see what ports are open on his/her computer. Of course, the user can opt for typing another IP address to check the open ports on other computers.
This website is such an open port check tool, a free online software to check ports.
It is only possible to check open ports when the user types in his/her computer’s current external IP address. If the user’s computer is connected to the internet, instead of directly connecting to the router, the test results are the same as to the router.
Port Numbers:
Ports can be identified by numbers from 0 to 65535. These numbers are attached to each port, like an address, so that they can direct the flow of Internet traffic. This is a limitation imposed by the TCP/IP protocol.
These system ports are used by system processes to provide widely used types of network services. The client’s program must always know the port to which it needs to connect to a remote server or to another network device. Because of this, most protocols allow ports only in the range from 0 to 1023.
The Internet Assigned Numbers Authority, also known as IANA, is responsible for maintaining the official assignments of port numbers for certain uses. However, many unofficial uses occur in practice.
For instance, when a person is surfing on the Internet, his/her browser instantly connects to port 80 on a remote server that hosts the site this person is surfing on (in case of HTTPS the port is 445). In response, the browser receives a set of data and codes in order to download and display a web page.
In order to check the computer’s port status inside a subnet, you have to use the port forwarding tool.
What is port forwarding:
Port forwarding is a configuration that needs to be made on the router. This action allows the router to redirect external requests to other computers or to other devices on the local network.
It is a way to determine which local computer to send data and connection requests to. These actions will eventually arrive at a specific port on the router.
For example, if a person has a web server connected to the Internet via a router and many other computers are also connected to the same router and access the same network to connect to the same server, the connection to the person’s server will not work without port forwarding outside of the Internet.
If the person’s computer is connected to the Internet directly, then the port forwarding tool is a must. All the open ports must be accessible from the Internet in order to connect to the server.
Online open port checkers are useful for finding out if your port forwarding is setup correctly or if your server applications are being blocked by a firewall.
These tools may also be used as port scanners to scan your network for ports that are usually forwarded, a port scanner can scan list or range of ports in a run and not only one port.
Did you know that some ports, such as port 25, are blocked most of the time at the ISP level in order to prevent malicious activity?
Any extraneous information that accidentally leaked out of your computer can easily be used by a malicious user to try to exploit known vulnerabilities or develop new ones.