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Subnetting Practice Quiz

CCNA / CCNP-level drills. Random IPv4 questions on network, broadcast, usable range, and mask with instant feedback.

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Score: 0
Click Start to begin.

How this quiz works

Each question is generated from a deterministic, seed-based pseudo-random source so practice rounds are reproducible per session. Difficulty controls the prefix-length range used to spawn random networks.

  • Question typesNetwork · Broadcast · First / last usable · Subnet mask · Usable host count
  • Per question4 options, single answer, instant feedback, math explanation
  • Score storageLocal only (localStorage), never sent to a server

Tips for fast subnetting in exams

  • Memorise the block-size table. A /27 has block size 32, a /28 has 16, a /29 has 8.
  • Find the network address first. Multiply the relevant octet by its block size and round down.
  • Broadcast = next network − 1. Often faster than masking.
  • Hosts = 2(32−N) − 2, except for /31 where RFC 3021 allows both addresses on point-to-point links.

How to use the subnetting practice quiz

  1. Pick a difficulty: Easy (/24 – /30), Mixed (/16 – /30), or Hard (/8 – /30).
  2. Click Start Quiz. Answer one question at a time with instant feedback.
  3. Track your accuracy across runs; stats are stored locally in your browser only.

Frequently asked questions

How can I practice subnetting fast for the CCNA exam?

Drill with 20 to 30 random subnetting questions per day. Memorise the block-size table and aim for under 30 seconds per question. Use this quiz with the Easy difficulty first, then Mixed, then Hard.

Why are subnetting questions still on the CCNA in 2026?

Even with IPv6 widely deployed, the fundamentals — binary maths, block sizes, network and broadcast detection — remain the basis for understanding every routing protocol and ACL.

What is the shortcut for finding the broadcast address?

Find the network address, then add (block size − 1) to the relevant octet. Faster than mask-by-OR in your head.

How do I get under one minute per subnetting question?

Memorise the powers of 2 to 2^16, the block size table for the fourth octet, and the rule 'broadcast = next network − 1'. Practice daily.