ITPEC FE Morning April 2022 Question 33
ITPEC FE Morning April 2022 — Question 33 of 80
IPv4 Host Address Calculation — find max usable hosts from CIDR notation.
Given network 172.16.64.0/23:
- •Prefix length =
23→ bits for hosts =32 - 23=9 - •Total addresses =
2^9=512 - •Usable hosts =
512 - 2=510(subtract network and broadcast)
Why not others:
- (a) 254 — applies to /24 (2^8 - 2)
- (b) 256 — total addresses for /24, not subtracting reserved
- (d) 512 — total addresses for /23, missing the -2 for network and broadcast
Key rule: Usable hosts = 2^(32 - prefix) - 2. Always subtract 2 for network address (all host bits 0) and broadcast address (all host bits 1).
AI-generated — may contain errors
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