Module 3
Filtering by Service
Adding protocol and port to a rule, which is the difference between an access list that expresses an intention and one that approximates it.
2 activities~29 min
In this module
- Permit one service rather than every service on a host
- Distinguish an open, refused and filtered port by the response
- Explain why a blocking rule should drop rather than reject
Activities
Lesson
Filtering by service, not just by host
Protocol, port, state, and the three answers a probe can get.
9 min
Lab
Permit one service, not one host
A host-level permit narrowed to a single port, without cutting off the administrators who need the other one.
20 min
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Curriculum topics
Each topic page lists every lesson, quiz and hands-on lab that covers it, plus how it maps onto the CCNA and Network+ blueprints.