CCNA Exam Preparation / IPv4 and IPv6 addressing
CCNA technique 048: Private IPv4 ranges — practice and verify
An original CCNA exercise on private ipv4 ranges 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
Classify 10.1.1.1, 172.31.1.1, 172.32.1.1, and 192.168.1.1 and explain the boundary at 172.16/12.
Expected reasoning
RFC 1918 private space is not the same thing as all non-public address space.
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 private ipv4 ranges 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.