NAT and firewall rules
Read NAT and firewall rules, publish a service safely, and spot rules that are too broad or in the wrong order.
- Level
- Intermediate
- Length
- About 45 minutes
- Contents
- 3 lessons · 1 video · final exam
- Status
- Published · updated 1 Oct 2026
Skills you'll practise
- Explain NAT, PAT and port forwarding
- Evaluate a rule list top to bottom, including the implicit deny
- Publish a service with the narrowest rule that works
- Recognize requests that should be refused or escalated
Course outline
- 1.NAT and firewall rules that do what you meantVideo · 2 min
- 2.How NAT and rules decideLesson · 16 min
- 3.Port forwards and NAT tables in practiceLesson · 16 min
- 4.Reading firewall logs and rule hitsLesson · 15 min
- 5.NAT and firewall rules: knowledge checkKnowledge check · 16 questions
- 6.NAT and firewall rules: practical exerciseKnowledge check · 1 question
- 7.Final exam7 questions · passing it completes the course, so people who already know the material can test out
Sources it draws on
The lessons and questions are written from these references, so learners can go back to the original.
- RFC 3022: Traditional IP Network Address Translator
- RFC 4787: NAT Behavioral Requirements for Unicast UDP
- Least-privilege firewall rule design
See it with your own jobs and topics
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