CCNA Exam Preparation / STP and wireless
CCNA technique 090: BPDU guard — practice and verify
An original CCNA exercise on bpdu guard with predictions, evidence, and a changed-condition check.
Environment and inputs: CCNA 200-301 v1.1 study; isolated Cisco IOS / IOS XE lab or paper exercise where applicable.
Practice task
Connect a simulated switch to the protected edge port and identify the evidence needed before restoring it.
Expected reasoning
An edge port protected by BPDU guard can be disabled when it receives a BPDU.
Produce evidence
Use an isolated simulator, approved lab or paper trace. Record the topology, prediction and observed result. Before device changes, capture the relevant interface, route, neighbor or service state. Ping alone may not prove the behavior under study.
Introduce a counterexample
Change one condition in the bpdu guard exercise and predict the result before checking it. Explain which observation would disprove your hypothesis. Restore the baseline, repeat from blank notes and keep both results.
Exam scope
Independent CCNA 200-301 v1.1 exercise, checked against Cisco resources on 2 November 2026. It is not a recalled exam question. The collection’s 200 techniques do not represent exam question counts or weights. Check Cisco’s current exam rules and your simulator’s supported syntax.