Network Security Basics Course

Lesson 1 • Network Models and Layered Architecture

Introduces the OSI and TCP/IP models as frameworks for understanding protocol interaction. Establishes vocabulary used throughout the course.

Lesson 2 • Network Topologies and Media Types

Surveys physical and logical topologies alongside wired and wireless media. Grounds students in infrastructure choices that affect security posture.

Lesson 3 • Core Network Protocols

Examines DNS, DHCP, ARP, and ICMP as essential operational protocols. Connects protocol behaviour to real network troubleshooting scenarios.

Lesson 4 • IP Addressing and Subnetting Basics

Covers IPv4 and IPv6 address structures, classes, and subnet masks. Enables students to design and interpret basic addressing schemes.

Lesson 1 • Security Policies and Governance Basics

Covers acceptable use, password, and incident response policies as governance tools. Establishes the policy layer that underpins all technical controls.

Lesson 2 • Vulnerability and Risk Fundamentals

Introduces vulnerability, threat, and risk as distinct but related concepts. Students use this framework to prioritise security investments throughout the course.

Lesson 3 • Authentication, Authorisation, and Accounting

Explains AAA as the framework governing identity and access on networks. Connects AAA components to device login, VPN, and network access control.

Lesson 4 • The CIA Triad and Security Goals

Defines confidentiality, integrity, and availability as the pillars of information security. Links each pillar to concrete network protection requirements.

Lesson 1 • Cryptographic Protocol Applications

Maps cryptographic primitives to TLS, SSH, and IPsec protocol operations. Reinforces why algorithm selection directly affects network security strength.

Lesson 2 • Hashing and Data Integrity

Introduces cryptographic hash functions and their role in verifying data integrity. Links hashing to digital signatures, certificates, and password storage.

Lesson 3 • Asymmetric Encryption and Key Exchange

Covers public-private key pairs, RSA, and elliptic curve cryptography. Explains how asymmetric methods solve the key distribution problem.

Lesson 4 • Symmetric Encryption Algorithms

Examines block and stream ciphers, key sizes, and modes of operation. Connects symmetric encryption to bulk data protection in network protocols.

Lesson 1 • Access Control List Design

Teaches ACL syntax, rule ordering, and implicit deny principles on routers and switches. Connects ACL logic to traffic filtering decisions in real topologies.

Lesson 2 • Network Address Translation and Security

Covers NAT types, PAT, and their role in hiding internal addressing from external networks. Explains NAT limitations as a security control.

Lesson 3 • Firewall Rule Auditing and Hardening

Addresses rule bloat, shadow rules, and periodic review processes for firewall policies. Prepares students to maintain a clean, effective rule base over time.

Lesson 4 • DMZ Architecture and Network Zones

Introduces the demilitarised zone as a buffer between untrusted and trusted networks. Students design multi-zone architectures that isolate public-facing services.

Lesson 1 • Designing a Segmented Network Architecture

Guides students through a structured process for mapping zones, trust levels, and inter-segment policies. Produces a complete segmentation design as a practical deliverable.

Lesson 2 • VLAN Security Attacks and Mitigations

Examines VLAN hopping, double-tagging, and rogue trunk attacks with their countermeasures. Reinforces that VLANs require hardening beyond default switch settings.

Lesson 3 • Segmentation Principles and Benefits

Explains why segmentation reduces attack surface and limits breach propagation. Frames segmentation as a foundational zero-trust building block.

Lesson 4 • Network Micro-Segmentation Techniques

Introduces software-defined and host-based micro-segmentation for granular east-west control. Extends segmentation concepts to virtualised and cloud-adjacent environments.

Lesson 1 • Network Traffic Analysis Techniques

Covers packet capture, flow analysis, and baseline profiling for anomaly identification. Builds the analytical skills needed to interpret monitoring data effectively.

Lesson 2 • Writing and Managing Detection Rules

Teaches rule syntax, condition logic, and alert thresholds for common IDS/IPS platforms. Connects rule quality directly to detection accuracy and operational noise.

Lesson 3 • Continuous Monitoring and Alerting Strategy

Establishes a monitoring programme with defined metrics, escalation paths, and review cycles. Prepares students to sustain detection capability beyond initial deployment.

Lesson 4 • IDS and IPS Fundamentals

Distinguishes detection-only IDS from inline IPS and explains signature vs. anomaly detection. Establishes the role of each in a layered defence strategy.

Lesson 1 • Zero Trust Network Access Principles

Introduces ZTNA as an evolution beyond perimeter VPN, enforcing per-session verification. Contrasts ZTNA with traditional VPN to highlight architectural differences.

Lesson 2 • Remote Access Security Requirements

Identifies the risks of remote connectivity and the controls needed to mitigate them. Frames endpoint trust, authentication strength, and channel encryption as core requirements.

Lesson 3 • IPsec VPN Architecture and Configuration

Covers IKE phases, SA negotiation, and tunnel vs. transport mode for site-to-site VPNs. Connects IPsec parameters to the cryptographic concepts from Chapter 3.

Lesson 4 • SSL/TLS VPN Solutions

Examines clientless and full-tunnel TLS VPN models and their use cases. Addresses split tunnelling, portal design, and certificate management for TLS VPNs.

Lesson 1 • Network Evidence Collection

Covers packet capture, log preservation, and chain-of-custody requirements for network evidence. Connects evidence integrity to the legal and organisational validity of findings.

Lesson 2 • Traffic and Log Analysis for Investigations

Applies packet and flow analysis to reconstruct attack timelines and identify compromised hosts. Builds on monitoring skills from Chapter 6 in an investigative context.

Lesson 3 • Incident Response Lifecycle

Maps the preparation, detection, containment, eradication, recovery, and lessons-learned phases. Provides the procedural framework applied in all subsequent forensic sections.

Lesson 4 • Incident Reporting and Lessons Learned

Guides students through writing technical incident reports and conducting structured post-mortems. Closes the response cycle with actionable improvements to prevent recurrence.