Network+ Protocols & Ports

FTP tcp/20 & tcp/21

Transfers file between systems

SFTP tcp/22

• Generic file transfer with security

• An extension of SSH to provide a secure method for transferring files

SSH tcp/22

Encrypted communication link

Telnet tcp/23

Transmits data in plaintext. Uses clear-text transmission (no encryption)

• Insecure

• Uses a client/server model

SMTP tcp/25

Standard protocol for email transmission across the internet

DNS tcp/53 & udp/53

Converts domain names to IP addresses

DHCP udp/67 & udp/68

Network management protocol that automatically assigns IP addressing information without manual configuration

• One for client server

• One for the client

TFTP udp/69

Simple, lock-step, file transfer protocol with no authentication, used for transferring files smaller in size

• Typically used for transferring boot files or configurations to devices in a local network, such as routers and switches

• Generally used in controlled environments due to its simplicity and lack of features

HTTP tcp/80

Communication for the web browser

• A stateless protocol, meaning each command is executed independently, without any knowledge of the commands that came before it

• Provides a standard for web browsers and servers to communicate

HTTPS tcp/443

A secured version used for web communication. Encrypts data between a client and a web server using:

• TLS (modern standard, improved, and much more secured than SSL)

• SSL (older standard)

NTP udp/123

Used to synchronize the clocks of computers over a network

• Provides high precision time correction to networked device

SNMP udp/161 & udp/162

Used for managing devices on IP networks

• Enables network admins to manage network performance, find and solve network problems, and plan for network growth

LDAP tcp/389 & udp/389

Protocol for accessing and maintaining distributed directory information services over an IP network

• Used for querying and modifying items in directory service databases like Microsoft Active Directory, OpenLDAP, and other directory services that follow the X.500 standard

• Provides a mechanism for connecting to, searching, and modifying internet directories

SMD tcp/445

Used for network file sharing, allowing computers to read and write files and request services from server programs in a computer network

• Used primarily by Windows systems for file sharing, network browsing, printing services, and inter-process communication

Syslog udp/514

Command is used to configure and manage system logging, which collects and stores log messages from network devices

• Sends log messages to a centralized syslog server for monitoring and analysis

• Helps in troubleshooting network issues, identifying security threats, and ensuring compliance by providing a detailed record of system events

SMTPS (Secure SMTP) tcp/587

A protocol for securing communications between email servers and clients

• Uses an encryption layer to enhance the security of data being transferred during email communications

LDAPS (Secure LDAP) tcp/636

Providing a secure method of accessing and maintaining distributed directory information services over an IP network

• Encrypts traffic using SSL

• Ensure confidentiality and integrity

SQL Server tcp/1433

A relational database management system (RDBMS) used to store, query, and manage structured data

RDP tcp/3389

Microsoft protocol that enables remote connections to other computers, primarily running Windows OS

• Widely used for remote administration, remote work, and IT support, offering encrypted and secure access to remote desktops and applications

SIP tcp/udp 5060/5061

A signaling protocol used for initiating, maintaining, modifying, and terminating real-time sessions that involve video, voice, messaging, and other communications applications and services