Network Security Engineering Full Course Notes

Course Introduction

• Overview of network security engineering.
• Basics suitable for beginners (Ethernet, network topologies).
• Explore TCP/IP and OSI models.
• Implementation of tools like Wireshark.
• Discuss subnetting and parity check.

What is Network Security?

• Set of technologies protecting usability and integrity of a company's infrastructure.
• Prevents unauthorized access and ensures security through multiple defense layers.
• Aims for confidentiality and accessibility of data.

Importance of Network Security

• Password protection as a basic solution.
• Central topic in cybersecurity with increasing demand for skilled professionals.
• Secures personal and organizational networks to prevent data loss, theft, and sabotage.

Components of Network Security

Key Concepts

• Authentication: Verifies the identity of users.
• Authorization: Determines access levels for authenticated users.

Types of Network Security

1. Physical Security: Protects hardware and network infrastructure from unauthorized access.
2. Technical Security: Focuses on securing data during storage and transmission.
3. Administrative Security: Policies and processes governing users' behavior and access rights.

Network Security Layers

Transport Layer Security

• Secures information during transmission (TLS for web browsers).
• Uses cryptographic methods for secure connections.

Application Layer Security

• Closest to end-users, vulnerable to attacks.
• Examples of application layer attacks: DDoS, SQL injections.
• Protection tools: firewalls, secure web gateways.

Tools for Network Security

1. Firewalls: Monitor and control incoming/outgoing traffic based on established security rules.
2. VPNs: Create encrypted connections over the internet for secure data transmission.
3. Intrusion Prevention Systems (IPS): Detect and respond to harmful activity in real-time.
4. Behavioral Analytics: Monitor network patterns to detect potential attacks.

Benefits of Network Security

• Protects against external/internal threats.
• Reduces downtime and enhances productivity.
• Builds brand trust and customer retention.

Networking Basics

Types of Networks

• LAN (Local Area Network): Connects devices over a small geographic area.
• WAN (Wide Area Network): Connects LANs over larger distances.

IP Addressing

• IPv4: 32-bit address, divided into classes (A, B, C, D, E).
• IPv6: 128-bit address, designed to expand addressable space.

Network Topology

• Arrangement of connected devices and their layout (bus, ring, star, tree, mesh).

Protocol Models

OSI Model

• 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, Application.

TCP/IP Model

• 4 layers: Application, Transport, Internet, Network Access.

DHCP (Dynamic Host Configuration Protocol)

• Automates IP address allocation to devices.
• Two allocation methods: manual and dynamic.
• Operation phases include client request and server acknowledgment.

Command Line Networking Tools

• ipconfig: Displays network configuration on Windows.
• ifconfig: Displays network configuration on Linux.
• ping: Tests connectivity to remote hosts.
• traceroute: Determines the path data takes to reach a destination.

Security Concepts

VPN (Virtual Private Network)

• Provides secure connections over the internet.
• Creates encrypted tunnels between clients and servers.

Firewall Types

1. Packet Filtering Firewall: Reviews packets based on source/destination addresses.
2. Proxy Firewall: Operates at the application layer, filtering traffic based on application protocols.
3. Stateful Firewalls: Track the state of active connections and make decisions based on the context.

Summary

• Network security is essential in safeguarding digital infrastructure.
• Continuous learning and upskilling are vital in this evolving landscape.
• Future applications include advanced cybersecurity practices and tools.