Ports & protocols

Transmission Control Protocol (TCP)

• Connection-oriented protocol

• Does a “handshake” before moving data

• Retransmits packets that didn’t arrive at their destination

• Ensures packets arrive in the correct order

• Prioritizes reliability over speed

User Datagram Protocol (UDP)

• Connectionless-oriented protocol

• Sends data without checking if it arrived

• Doesn’t care if data arrived in the correct order

• Prioritizes speed over reliability

IP Security (IPSec)

Set of protocols used for security at layer 3 of the OSI model.

Port

A conceptual “address” that allows a system to direct incoming data to the correct application or service.

TCP/IP

Transmission Control Protocol Over IP

Domain Name System (DNS)

Translates domain names to IP addresses.

Dynamic Host Configuration Protocol (DHCP)

Dynamically assigns IP information to devices on a network.

HyperText Transfer Protocol (HTTP)

Set of rules used to send & receive data on the world wide web.

HTTPS

Secure version of HTTP using encryption and digital certificates.

File Transfer Protocol (FTP)

A set of rules that allows users to upload, download, rename, and manage files over a network.

Secure Shell (SSH)

Allows secure access of computers over a network using a command-line interface.

Simple Mail Transfer Protocol (SMTP)

Takes emails & delivers them to the recipient’s mail server.

Transport Layer Security (TLS)

Encrypts data & authenticates servers/sites to ensure data integrity using certificates.

POP3

Used by email programs to get messages from a mail server onto a device.

IMAP

Keeps messages stored on a remote server.