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Module 2: fastest way to find which subnet a host belongs to?

itayitayy · posted Jun 4, 2026 · 40 views

I'm on the Addressing module and the subnetting drills are killing me on time.

Given 172.16.20.45/27, how do I work out the network address and the valid host range quickly, without long division? Is there a trick people actually use in the exam?

subnettingaddressingipv4exam
  • Same — the magic-number method is the only reason subnetting finally clicked for me. — ben31833, Jun 5, 2026

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