Chapter 4 of 5 · CompTIA Network+ N10-009

Network Security

Core concepts, encryption, identity, attacks, device hardening, ACLs, firewalls and security zones.

  • 7topics
  • 32 minfast track
  • 2diagrams and exhibits
  • 14%of the exam
Start with Core Network Security Concepts

Topics in this chapter

Take them in order, or jump to the one you need.

  1. 1Core Network Security ConceptsLearn the CIA triad, threats, vulnerabilities and exploits, risk assessments, defense in depth, least privilege, RBAC, zero trust…5 min
  2. 2Encryption and CertificatesUnderstand encryption in transit and at rest, symmetric and asymmetric keys, TLS, public key infrastructure, CAs and self-signed…4 min
  3. 3Identity and Access ManagementCompare AAA, multifactor authentication, SSO, RADIUS, TACACS+, LDAP, SAML, Kerberos and 802.1X port based authentication used to…Diagram5 min
  4. 4DoS, Layer 2 and Spoofing AttacksRecognize DoS and DDoS, VLAN hopping, MAC flooding, ARP poisoning, DNS poisoning, rogue DHCP servers and access points, evil…5 min
  5. 5Social Engineering and MalwareLearn social engineering such as phishing, tailgating, shoulder surfing and dumpster diving, plus malware types and how to limit…4 min
  6. 6Device Hardening and Access ControlHarden network devices by closing unused ports and changing defaults, then control access with port security, 802.1X, MAC…4 min
  7. 7ACLs, Firewalls and Security ZonesApply ACLs, stateless and stateful firewalls, URL and content filtering, IDS and IPS, and trusted, untrusted and screened subnet…Diagram5 min

About this chapter

What this chapter covers

Network Security explains how to protect a network and how attackers try to defeat it. It covers the basic concepts, the attacks you must recognize and the defenses you must apply.

The chapter follows the fourth exam domain and has three syllabus topics: basic network security concepts, types of attacks and their impact, and network security features, defense techniques and solutions.

How the topics fit together

The pages move from principles to threats to controls. First you learn the goals and tools of security, then the attacks that break them, then the features that stop them.

Security conceptsCIA, IAM, encryptiondefine goals forAttacksDoS, spoofing, malwarecountered byDefenseshardening, ACLs, firewalls
  • Core concepts, encryption and identity give the vocabulary and the building blocks.
  • Attacks are grouped into network level attacks and people and malware attacks.
  • Hardening and access control reduce what an attacker can reach on devices and ports.
  • ACLs, firewalls and zones control traffic between parts of the network.
Exam tip

For each attack in the second half of the chapter, learn its matching defense at the same time. Exams often ask for the defense by describing the attack.

How to use these pages

Each topic page has the same shape, so you can skim for what you need.

  • What it is: the idea in plain words.
  • How it works: the mechanism, with diagrams, tables and example commands.
  • What to remember for the exam: the facts to memorize.
  • Common mistakes: the classic traps.
  • Check yourself: three questions to test your understanding.

Read the pages in order the first time. Then use the exam facts and the questions for revision.

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