Computer Networks · M2 · mocks

Q1B · Host bits and address counts

M2 mock A

Q1(a)+Q1(b) compulsory; choose any two of Q2/Q3/Q4 · 10 marks attempted

Question. For IPv4 /27, find the number of host bits, total addresses and ordinary usable host addresses. [2 practice marks]

Answer

Given

p=27; ordinary IPv4 broadcast subnet.

To find

h, total and usable counts.

Formula and why

h=32-p,\quad N=2^h,\quad U=N-2LaTeX: h=32-p,\quad N=2^h,\quad U=N-2

Two boundary addresses are reserved under these ordinary rules.

Step-by-step solution

  1. Host bits: 32−27=5.
  2. Total addresses: 2⁵=32.
  3. Usable hosts: 32−2=30.

Final answer: 5 host bits, 32 total, 30 usable.