This document describes common server ports. For more information on service application ports for Windows, see Service Overview and Network Port Requirements for Windows.
|21||FTP||An open FTP server port for uploading and downloading.|
|22||SSH||An SSH port for remotely connecting to Linux servers in CLI mode.|
|25||SMTP||An open SMTP server port for sending emails.|
|80||HTTP||A port for web services, such as IIS, Apache, and Nginx, to provide external access.|
|110||POP3||A port for the POP3 (email protocol 3) service.|
|137, 138, 139||NetBIOS protocol||Ports 137 and 138 are UDP ports for transferring files through My Network Places.
Port 139: connections established through port 139 attempt to access the NetBIOS/SMB service. This protocol is used for file and printer sharing on Windows and SAMBA.
|143||IMAP||A port for Internet Message Access Protocol (IMAP) v2, which is a protocol for receiving emails like POP3.|
|443||HTTPS||A port for web browsing. HTTPS is a variant of HTTP that provides encryption and transmission over secure ports.|
|1433||SQL Server||Default port for SQL Server. The SQL Server service uses two ports: TCP-1433 and UDP-1434. Port 1433 is used to provide external services, and port 1434 is used to return a response to the requester to indicate the TCP/IP port used by SQL Server.|
|3306||MySQL||Default port for MySQL databases, which is used by MySQL to provide external services.|
|3389||Windows Server Remote Desktop Services||Service port for the Windows Server remote desktop, through which you can connect to a remote server by using the "Remote Desktop" connection tool.|
|8080||Proxy port||Similar to port 80, port 8080 is used in the WWW proxy service for web browsing. The port number ":8080" is often appended to the URL when you visit a website or use a proxy. In addition, after the Apache Tomcat web server is installed, its default service port is port 8080.|