During the operation and maintenance process, it is crucial to understand common ports and their corresponding services. A port is the interface through which a computer communicates with the network, while a service is an application that runs on a specific port. This article introduces 20 ports and their corresponding services that are frequently used in operation and maintenance work to help you better manage and maintain the system.

Commonly used ports and services list

(1) Port number: 21

Service name: FTP

Service Description: File transfer protocol, used to transfer files between clients and servers.

(2)  Port number: 22

Service Name: :SSH

Service Description: Secure Shell protocol for secure remote login and command execution in the network.

(3)  Port number: 23

Service name: Telnet

Service description: Used to remotely log in to the remote host and execute commands.

(4) Port number: 25

Service name: SMTP

Service Description: Simple Mail Transfer Protocol, used for sending email.

(5) Port number: 53

Service name: DNS

Service description: Domain name system, used to resolve domain names into corresponding IP addresses.

(6) Port number: 80

Service name: HTTP

Service Description: Hypertext Transfer Protocol, used to transfer data between web browsers and web servers.

(7) Port number: 110

Service name: POP3

Service Description: Post Office Protocol version 3, used to receive emails from mail servers.

(8) Port number: 143

Service name: IMAP

Service Description: Internet Message Access Protocol, used to receive and manage email from mail servers.

(9) Port number: 161

Service name: SNMP

Service Description: Simple Network Management Protocol, used to manage and monitor network devices.

(10) Port number: 443

Service name: HTTPS

Service Description: Secure Hypertext Transfer Protocol protects Web data transmission through encrypted communication.

(11) Port number: 465

Service name: SMTPS

Service Description: An encrypted version of SMTP for sending email securely.

(12) Port number: 587

Service name: SMTP

Service Description: Another common port for SMTP, used for sending emails.

(13) Port number: 993

Service name: IMAPS

Service Description: An encrypted version of IMAP for securely receiving and managing email.

(14) Port number: 995

Service name: POP3S

Service Description: An encrypted version of POP3 for receiving email securely.

(15) Port number: 1433

Service name: MSSQL

Service Description: The default port of the Microsoft SQL Server database management system.

(16) Port number: 1521

Service name: Oracle

Service description: The default port of the Oracle database management system.

(17) Port number: 3306

Service name: MySQL

Service description: The default port of the MySQL database management system.

(18) Port number: 3389

Service name: RDP

Service Description: Remote Desktop Protocol, used to access and control computers remotely.

(19) Port number: 5432

Service name: PostgreSQL

Service description: The default port of the PostgreSQL database management system.

(20) Port number: 8080

Service name: HTTP

Service description: Alternative port for HTTP, commonly used in proxy servers and development environments.

My summary

It is very important for operation and maintenance personnel to understand common ports and their corresponding services. By having basic knowledge of these ports and services, you can better diagnose and solve network and system problems. At the same time, proper configuration and management of these services can also improve system security and performance. I hope this article will be helpful to your operation and maintenance work!