TCP / UDP PORTS

137, 138,139 Server Message Block (SMB) over NetBIOS

NetbIoS is a legacy suite of protocols used by windows before TCp/IP. to support legacy NetBIOS applications on a TCP/IP network, TCP offers NetbIoS over TCP/IP. earlier versions of Smb required NetbIoS over TCP/IP be enabled. ports used on these networks are: SMB over UDP uses ports 137 and 138. SMB over TCP uses ports 137 and 139. Current versions of Smb don't require NetbIoS over tCp.

3389 Remote Desktop Protocol (RDP) apps, including Remote Desktop and Remote Assistance

Remote Desktop and Remote Assistance listen at port 3389

20 File Transfer Protocol (FTP) Client

The File Transfer Protocol (FTP) Client receives data on port 20 from the FTP server

21File Transfer Protocol ( FTP) Server

The File Transfer Protocol (FTP) server listens on port 21 for commands from an FTP client

143 Internet Message Access Protocol (IMAP) email client

An email client using IMAP receives email at port 143

110 Post Office Protocol, version 3 (POP3) email client

An email client using POP3 receives email at port 110

23 Telnet Server

A Telnet server listens at port 23

22 Secure Shell (SSH) Server

A server using the Secure Shell (SSH) protocol listens at port 22

443 Web server using Hypertext Transfer Protocol (HTTP)

A web server listens at port 443 when receiving HTTPS transmissions

80 Web server using Hypertext Transfer Protocol (HTTP)

A web server listens at port 80 when receiving HTTP transmissions

548 Apple Filing Protocol (AFP)

AFP over TCP/IP is used for file sharing and file services

445 Server Message Block (SMB) direct over Transmission Control Protocol (TCP)/Internet Protocol (IP)

Current releases of SMB and SMB2 use port 445 for both TCP and User Datagram Protocol (UDP) traffic

53 Domain Name Server or Domain Name Service (DNS)Server

Domain Name Server or Domain Name Service (DNS) A DNS server listens at port 53

427 Service Location Protocol (SLP) and Apple Filing Protocol (AFP)

Service Location Protocol (SLP) uses port 427 to find printers and file sharing devices on a network. AFP relies on SLP and port 427 to find resources on a local network

25 Simple Mail Transfer Protocol (SMTP) email server

Simple Mail Transfer Protocol (SMTP) An email server listens at port 25 to receive email from a client computer