2.1 - Ports and their Purposes

TCP/20

Active Mode Data

TCP/21

Control

TCP/22

Encrypted communication link

TCP/23

• Telecommunication network

• login to devices remotely

TCP/25

Server to server email transfer

UDP/53

Converts names to IP addresses

UDP/67

Automated configuration of IP address, subnet mask and other options (server-side)

UDP/68

Automated configuration of IP address, subnet mask and other options (client-side)

TCP/80

Web server communication

TCP/443

Web server communication with encryption

TCP/110

Receive emails from email server, basic mail transfer functionality

TCP/143

Receive emails from email server, includes management of email inbox from multiple clients

UDP/137

name resignation and resolution for NetBIOS over TCP/IP

TCP/139

session-based communication for file and printer sharing over NetBIOS

TCP/445

direct SMB communication over TCP without the NetBIOS transport

TCP/389

store and retrieve information in a network directory

TCP/3389

shares a desktop from a remote location