Networking Protocols and Associated Port Numbers

File Transfer Protocol (FTP)

• FTP (File Transfer Protocol):
  • Used for file transfers across various operating systems like Linux, Windows, Mac OS.
  • Utilizes two port numbers:
    • TCP Port 20: Used for the actual file transfer process.
    • TCP Port 21: Used for sending control information.
  • Supports authentication using usernames and passwords.
  • Allows file management tasks: listing directories, adding, deleting, renaming files.

Secure Shell (SSH)

• TCP Port 22: Associated with SSH.
  • Used for secure remote communication with devices via a text-based command line interface.
  • Encrypts communication to enhance security.

Secure FTP (SFTP)

• SFTP:
  • Secure version of FTP using SSH for encryption.
  • Uses the same port as SSH: TCP Port 22.
  • Supports secure file management with encryption.

Telnet

• TCP Port 23:
  • Non-encrypted terminal communication protocol.
  • Sends information in clear text, risking exposure of credentials.
  • Replaced by SSH due to lack of encryption.

Simple Mail Transfer Protocol (SMTP)

• TCP Port 25:
  • Used for server-to-server email transfers, in plain text.
• TCP Port 587:
  • SMTP with TLS encryption for secure email transmission.

Internet Message Access Protocol (IMAP) and Post Office Protocol 3 (POP3)

• IMAP/POP3: For receiving and managing emails, complementing SMTP for sending emails.

Domain Name System (DNS)

• UDP Port 53:
  • Resolves domain names to IP addresses for small queries.
• TCP Port 53:
  • Used for large data transfers between DNS servers.

Dynamic Host Configuration Protocol (DHCP)

• UDP Port 67 and 68:
  • Automatically assigns IP addresses and configuration settings.
  • Utilized by both home routers and enterprise DHCP servers.

Trivial File Transfer Protocol (TFTP)

• UDP Port 69:
  • Simple, quick file transfers without authentication.
  • Often used for transferring configuration files to devices like VoIP phones.

Hypertext Transfer Protocol (HTTP) and HTTP Secure (HTTPS)

• TCP Port 80:
  • Standard web communication without encryption.
• TCP Port 443:
  • Encrypted web communication using HTTPS.

Network Time Protocol (NTP)

• UDP Port 123:
  • Synchronizes clocks on network devices to ensure accurate timekeeping.

Simple Network Management Protocol (SNMP)

• UDP Port 161:
  • Manages and monitors network devices, querying performance data.
• SNMP Versions:
  • Version 1: Basic, non-encrypted communication.
  • Version 2: Supports bulk transfers, also non-encrypted.
  • Version 3: Provides encryption and enhanced security.
• UDP Port 162: Used for SNMP traps, allowing devices to send alerts to a management station.

Lightweight Directory Access Protocol (LDAP)

• TCP Port 389: Standard port for accessing directory services.
• TCP Port 636: Secure version using encryption.

Server Message Block (SMB) / Common Internet File System (CIFS)

• TCP Port 445:
  • Facilitates file and printer sharing on Microsoft networks.
  • Integrated into Windows OS without needing additional software.

Syslog

• UDP Port 514:
  • Transfers log files from network devices to centralized storage or a Security Information and Event Manager (SIEM).

Structured Query Language (SQL)

• TCP Port 1433:
  • Commonly used by Microsoft SQL Server for database queries.

Remote Desktop Protocol (RDP)

• TCP Port 3389:
  • Allows remote desktop access for Windows and other platforms.

Session Initiation Protocol (SIP)

• TCP Port 5060 and 5061:
  • Manages VoIP calls and sessions, including video conferencing and instant messaging.