CompTIA A+ - Firewall Ports and Functions

TCP/20, TCP/21

FTP

File Transfer Protocol

Send and Receive files between systems, Authenticates with Username and Password

TCP/22

SSH

Secure Shell

Encrypted Console Access

TCP/23

Telnet

Telecommunication Network

Un-Encrypted console access, Same as SSH but unsecure

TCP/25

SMTP

Simple Mail Transfer Protocol

Primarily for Sending Mail, Commonly used for Smartphones and Email Clients, Transfer Email between Mail Servers

UDP/53, TCP/53

DNS

Domain Name System

Converts IP address to human searchable name, Convert Domain Names to IP Address

UDP/67, UDP/68

DHCP

Dynamic Host Configuration Protocol

Automate IP Address allocation when a device is connected to a network.

TCP/80

HTTP

HyperText Transfer Protocol

Un-Encrypted Web Server Communication

TCP/443

HTTPS

HyperText Transfer Protocol Secure

Encrypted Web Server Communication

TCP/110

POP3

Post Office Protocol v3

Receive Email into a web client, Older Protocol

TCP/143

IMAP4

Internet Message Access Protocol v4

Receive Email into a web client, Newer Protocol

UDP/137

NetBIOS

NetBIOS Name Service

Register, Remove, and Find Windows Services by Name

TCP/139

NetBIOS

NetBIOS Session Service

Windows connection-oriented Data Transfer

TCP/445

SMB

Server Message Block

Windows FIle Transfers, Printer Sharing, and other Windows related Tasks

TCP/389

LDAP

Lightweight Directory Access Protocol

User Login Services, Directory Services, Microsoft Active Directory

TCP/3389

RDP

Remote Desktop Protocol

Port is same regardless of OS, Graphical display of remote devices, Remote Desktop