What is Port? – Scaler Topics

Virtual points where network connections begin and stop are called ports. Ports are software-based and controlled by operating system. Each port is connected to a different procedure or service. Ports allow computers to easily differentiate between different kinds of traffic: emails go to a different port number than webpages, for example , even though both reach a computer over the same Internet connection. Port number is a 16-bit logical address which is assigned to every application of your device and used to transmit data between computer network and application.

A port is just like a physical docking point which is used to connect the external device to the computer. A Port can also be considered as a programmatic docking point by which information transmits from a program to the computer or over the Internet.

Port numbers in networking manage the multiple transmission request by a single physical network on a computer. Port has two main applications in a computer network which are given below:

Port is a concept of the transport layer of an OSI suite. Transport layer protocol such as UDP(User Datagram Protocol) and TCP(Transmission Control Protocol) has a section in their headers for indicating the port number. Network layer protocol such as IP protocol header only contains the destination IP address, not the port number.

What are the Different Port Numbers?

Port numbers in the networking range from 0 to 65535. The Internet Assigned Numbers Authority (IANA) is responsible for maintaining the list of Port numbers. Internet Assigned Numbers Authority (IANA) manages the network-related protocols. There are commonly used port numbers with their associated network protocol.

• Ports 20 and 21: FTP stands for File Transfer Protocol and is used to transmit files between a client and a serve and uses port numbers 20 & 21.

• Network Port 22: The Protocol Secure Shell (SSH) uses port number 22 and creates secure network connections.

• Port 25: Simple Mail Transfer Protocol (SMTP) uses port number 25 and it is utilized in transmitting mail.

• A Port 80: Hypertext Transfer Protocol (HTTP) is the protocol that allows accessing web pages over the World Wide Web and uses port number 80.

• Port 123: Network Time Protocol (NTP) use port number 123 and allows the computer clocks to sync. This process is required for the encryption process.

• Port 179: Border Gateway Protocol (BGP) utilizes port number 179 and it is required for establishing efficient routes among the extensive networks that make up the Internet.

• Port 443 stands for HTTP Secure and it is the secure and encrypted version of HTTP. All HTTPS web traffic goes to port number 443.

• Port 500: Internet Security Association and Key Management Protocol (ISAKMP) uses port number 500 and it is part of the process of configuring secure IPsec connections.

• Port 3389: Remote Desktop Protocol (RDP) uses port number 3389 port number and it allows users to connect remotely to their desktop computers and another device.

Below is an image to show different well-known ports