Overview: This document covers the foundational concepts of networking, essential for understanding cybersecurity.
Networking is the practice of connecting computers and other devices to share resources. Understanding networking is crucial in cybersecurity, as it enables ethical hackers to discover and secure vulnerabilities.
Note: Networking is fundamental for penetration testing, especially when mapping out and scanning target systems.
An IP (Internet Protocol) address is a unique identifier assigned to each device on a network. IP addresses are typically in the form of IPv4 or IPv6.
Examples:
- IPv4:
192.168.1.1 - IPv6:
2001:0db8:85a3:0000:0000:8a2e:0370:7334
Subnetting divides a large network into smaller, manageable sections (subnets). It improves network efficiency and security.
Example Calculation: To calculate the subnet mask, use the IP and CIDR notation (e.g.,
192.168.1.0/24).
Protocols are rules governing data transfer. Key protocols include:
- TCP (Transmission Control Protocol): Reliable data transfer.
- UDP (User Datagram Protocol): Faster, but less reliable.
Ports are virtual endpoints for network communication. Some important ports are:
- 80: HTTP
- 443: HTTPS
- 22: SSH
- 21: FTP
Tip: Knowing ports and services is essential for scanning and identifying network services during penetration testing.