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Sniffing

Capture and read network traffic, and the attacks that make it possible.

10 units~76 minIntermediate levelDomain 3 of exam

About this module

Sniffing is capturing the packets travelling across a network. Admins sniff to troubleshoot; attackers sniff to steal passwords sent in clear text. On a switched network they must actively trick the switch first — MAC flooding, ARP poisoning, DHCP and DNS attacks. This module covers each one and, defense-first, how switch security and encryption shut them down.

What you will learn

  • Sniffing: passive vs active, vulnerable protocols
  • How switches, MAC addresses and the CAM table work
  • MAC flooding and port security
  • DHCP starvation and DHCP snooping
  • ARP poisoning and Dynamic ARP Inspection
  • MAC/DNS spoofing, Wireshark and countermeasures

Module roadmap

01Sniffing BasicsLesson 1 · ~4 min
02How Switches Work: MAC & the CAM TableLesson 2 · ~5 min
03MAC AttacksLesson 3 · ~4 min
04DHCP AttacksLesson 4 · ~4 min
05ARP PoisoningLesson 5 · ~5 min
06MAC & DNS SpoofingLesson 6 · ~4 min
07Sniffing Tools & TechniquesLesson 7 · ~4 min
08Sniffing CountermeasuresLesson 8 · ~4 min
09Lab: Capture & Read Your Own TrafficLab · ~35 min
10AssessmentAssessment · ~5 min

How to study: read a lesson → answer its 2 "Check yourself" questions → do the lab → pass the assessment with 80%+. Lessons 2, 3 and 5 are the most tested. The lab captures only your own lab traffic.