How to review CCNA practice questions so a miss becomes a lab
Sort every missed CCNA question into one of four causes: a concept gap, a command-recall gap, a subnetting-arithmetic slip or a misread question. Then turn the miss into the right action: a lab, a drill or a slower read. If you miss three or more in one domain, add lab hours there before you book.
Doing a hundred practice questions and reading the answers is not practice. It is a long way of feeling busy.
Why most review does not work
A candidate reads the explanation, nods and moves to the next question. A week later the same mistake returns. Review fails when it ends at understanding. CCNA rewards the skill of typing and finding, so the review must end in something you do.
Four causes of a miss
| Cause | What it looks like | The right action |
|---|---|---|
| Concept gap | You did not know what the feature does | Reread once, then build it in the lab |
| Command-recall gap | You knew the idea but not the command | Type it from a blank screen, three times |
| Arithmetic slip | You knew the method but got the number wrong | Add subnetting drills to the daily routine |
| Misread question | The answer was in the question | Slow down; underline the verb and the object |
Write the cause beside each miss. After one week of filling it in, the same one or two causes will keep appearing, and they are your plan for the next week.
Three questions to try
These are original questions written for practice. They are not Cisco questions.
Question 1. A host on VLAN 20 cannot reach another host on VLAN 20 on the other switch. VLAN 10 works across the same trunk. What is the most likely cause?
A. The trunk's allowed list omits VLAN 20. B. The router has no default route. C. OSPF is in the wrong area. D. The hosts use different subnet masks on VLAN 10.
Answer: A. Traffic for one VLAN failing while another works across the same trunk points to the allowed VLAN list. Routing is not involved when both hosts are in the same VLAN.
Question 2. How many usable host addresses does a /28 subnet provide?
A. 14 B. 16 C. 30 D. 62
Answer: A. A /28 leaves 4 host bits. Two to the power of 4 is 16, minus the network and broadcast addresses, gives 14.
Question 3. Two OSPF routers share a link but remain in the Init state. What should you check first?
A. Whether one side is blocking OSPF hellos with a filter. B. The interface bandwidth. C. The hostname of each router. D. The spanning-tree root.
Answer: A. Init means a hello was received but the neighbour has not seen you. A filter or one-way communication problem fits best.
Sort your misses by cause before you read the explanations.
Turn the table into a plan
After every set of ten, count the causes. Then apply a rule: three or more misses in one domain means you add lab hours there before you book. If most misses are misread questions, practise reading with a timer rather than studying more content.
How many practice questions are enough?
Enough to see a stable pattern, which for most candidates is several hundred over the whole plan. Quality matters more than quantity. The book's practice stage takes about 30 per cent of your hours and includes troubleshooting labs, subnetting drills and question sets by domain.
Rhythm for the week
- Monday to Thursday: ten questions, causes recorded.
- Friday: one lab built from the week's most common cause.
- Weekend: a timed set of twenty, and a look at the trend.
Choose one question source
Choose one bank for the practice stage and finish it.
Questions readers ask
How many CCNA practice questions should I do?
Should I memorise practice questions?
What score on practice tests means I am ready?
This article is independent and is not endorsed by Cisco. Facts change: confirm them on the official page before you act.