What is a port in a computer network

what is a port in a computer network.

What is a port in a computer network


What is Port


In a computer network, of course, we often hear the word port. while the port also has a number which is part of the addressing information used to identify the sender and recipient of the message. They are associated with TCP/IP network connections and may be described as a kind of add-on to IP addresses. So what exactly is meant by that port?


Also Read: Difference Between Static And Dynamic IP Address

TABLE OF CONTENTS

1. What Are Ports?

2. How Ports Work

3. TCP And UDP Port Category

4. Famous Port

5. Registered Port

6. Da Private Dynamic Port

7. Conclusion


What are Ports?


If you can consider all the addresses that a computer processor can use as an address space, then a particular address will have a special purpose. For example, an address can be a memory address or another address can be a port address. A port address can be used to talk to an external process or device. A port, then, is simply a hole in the processor's address space where data can be sent and received.


Each network process or device uses a specific network port to send and receive data. This means that it listens for incoming packets whose destination port matches that port number, and transmits outgoing packets whose source port is set to that port number. Processes can use multiple network ports to receive and send data.


Port numbers that range from 0 to 1023 are known as well-known port numbers. Well-known port numbers are allocated to standard server processes, such as FTP and Telnet. They are referenced by system processes that provide the most widely used types of network services.


Specific port numbers are assigned and recorded by the Internet Assigned Numbers Authority (IANA). However, in general practice, there is a lot of unofficial use of both officially defined numbers and unofficial numbers. In addition, some network ports are used for some applications and can be designated as official or unofficial.


How Ports Work

The port number is associated with network addressing. In a TCP/IP network, both TCP and UDP use their own set of ports that work in conjunction with IP addresses. This port number works like a telephone extension. Just as a business telephone switchboard can use a primary phone number and assign each employee an extension number (such as x100, x101, etc.), so a computer can have a primary address and a set of port numbers to handle incoming and outgoing connections.


In the same way that one phone number can be used for all employees in the building, a single IP address can be used to communicate with different types of applications behind a single router, an IP address identifies a destination computer and a port number identifies a specific destination application.


Is this true mail applications, file transfer programs, web browsers, etc. When you request a website from your web browser, the browser communicates over port 80 for HTTP , so the data is then sent back over the same port and displayed in a program that supports that port (web browser).


In TCP and UDP, port numbers start at 0 and move up to 65535. Numbers in the lower range are dedicated to common internet protocols such as port 25 for SMTP and port 21 for FTP. To find the special values ​​used by a particular application.


TCP And UDP Port Category


Famous Port


When IP is being implemented, there is a slow start in assigning services that need to use certain ports. Ports are initially assigned from the lowest port number and work their way up. Ports 0–1023 are considered well-known ports because they are used by many core services on Unix servers, and most of the required privileges on the server are implemented. Telnet (23) and Simple Mail Transport Protocol (SMTP) (25) are two examples of this service.


Registered Port


The Internet Assigned Number Authority (IANA) maintains a list of all services running on well-known ports and on all registered ports. The registration process establishes a permanent association with the port and service number. All of these services are long-term services and will be assigned to ports between 1,024 and 49,151. Microsoft Remote Desktop Protocol (RDP) (3389) and Network File System (NFS) (2049) are two examples of listed ports.


Da Private Dynamic PortsÂ


All other ports, from 49,152 to 65,535, are referred to as dynamic, or private ports. These ports are not permanently associated with any service. If you write your own service, you can configure it to use whatever dynamic port you want, but someone else can write their own service and use the same port.


This won't cause any problems until you install both services on the same IP host because they both want to use the same port, and that's not possible. It would be like two people plugging their phones into the same plug and socket at the operator's office, this is impossible. This problem shouldn't happen, if you have registered ports to work with because other developers can't use the same service.


Conclusion


So What Does That Port Mean? A port is an endpoint for a logical connection or a dedicated place to physically connect to some other device, usually with sockets and plugs of some kind. The port number identifies what type of port it is. For example, port 80 is used for HTTP traffic.

The port number is associated with network addressing. In a TCP/IP network, both TCP and UDP use their own set of ports that work in conjunction with IP addresses. This port number works like a telephone extension. Just as a business telephone switchboard can use a primary phone number and assign each employee an extension number (such as x100, x101, etc.), so a computer can have a primary address and a set of port numbers to handle incoming and outgoing connections .


In the same way that one phone number can be used for all employees in the building, a single IP address can be used to communicate with different types of applications behind a single router, an IP address identifying a destination computer and a port number identifying a specific destination applications.


Is this true mail applications, file transfer programs, web browsers, etc. When you request a website from your web browser, the browser communicates over port 80 for HTTP , so the data is then sent back over the same port and displayed in a program that supports that port (web browser).


In TCP and UDP, port numbers start at 0 and move up to 65535. Numbers in the lower range are dedicated to common internet protocols such as port 25 for SMTP and port 21 for FTP. To find the special values ​​used by a particular application.


TCP And UDP Port Category


Famous Port


When IP is being implemented, there is a slow start in assigning services that need to use certain ports. Ports are initially assigned from the lowest port number and work their way up. Ports 0–1023 are considered well-known ports because they are used by many core services on Unix servers, and most of the required privileges on the server are implemented. Telnet (23) and Simple Mail Transport Protocol (SMTP) (25) are two examples of this service.


Registered Port


The Internet Assigned Number Authority (IANA) maintains a list of all services running on well-known ports and on all registered ports. The registration process establishes a permanent association with the port and service number. All of these services are long-term services and will be assigned to ports between 1,024 and 49,151. Microsoft Remote Desktop Protocol (RDP) (3389) and Network File System (NFS) (2049) are two examples of listed ports.


Da Private Dynamic PortsÂ


All other ports, from 49,152 to 65,535, are referred to as dynamic, or private ports. These ports are not permanently associated with any service. If you write your own service, you can configure it to use whatever dynamic port you want, but someone else can write their own service and use the same port.


This won't cause any problems until you install both services on the same IP host because they both want to use the same port, and that's not possible. It would be like two people plugging their phones into the same plug and socket at the operator's office, this is impossible. This problem shouldn't happen, if you have registered ports to work with because other developers can't use the same service.


Conclusion


So What Does That Port Mean? A port is an endpoint for a logical connection or a dedicated place to physically connect to some other device, usually with sockets and plugs of some kind. The port number identifies what type of port it is. For example, port 80 is used for HTTP traffic.

Hopefully, this article about What is a port in a computer network, gives you a little insight. Also, read an article about What is a Programming Language: Definition, Types, and Examples that you may need to know. Thank you.

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