Exam N10-009 Topic 3 Question 12 Discussion
Actual exam question for CompTIA's N10-009 exam
Question #: 12
Topic #: 3
Question #: 12
Topic #: 3
A network administrator prepares a VLAN for a new office while planning for minimal IP address waste. The new office will have approximately 800 workstations. Which of the following network schemes meets the requirements?
Suggested Answer: A Vote an answer
To support about 800 workstations with minimal IP waste, you choose the smallest subnet that provides at least 800 usable host addresses. In IPv4, usable hosts per subnet are calculated as 2^(host bits) # 2 (subtracting network and broadcast addresses). A /22 leaves 10 host bits (32 # 22 = 10), providing 2^10 # 2 =
1024 # 2 = 1022 usable addresses-enough for 800 devices with relatively low waste.
Check the other options: /23 leaves 9 host bits, giving 2^9 # 2 = 512 # 2 = 510 usable addresses, which is not enough. A /21 provides 2^11 # 2 = 2048 # 2 = 2046 usable addresses-enough, but wastes more than /22. A
/20 provides 2^12 # 2 = 4096 # 2 = 4094 usable addresses-much more waste.
Therefore, 10.0.100.0/22 is the best choice that meets the workstation requirement while minimizing unused addresses.
1024 # 2 = 1022 usable addresses-enough for 800 devices with relatively low waste.
Check the other options: /23 leaves 9 host bits, giving 2^9 # 2 = 512 # 2 = 510 usable addresses, which is not enough. A /21 provides 2^11 # 2 = 2048 # 2 = 2046 usable addresses-enough, but wastes more than /22. A
/20 provides 2^12 # 2 = 4096 # 2 = 4094 usable addresses-much more waste.
Therefore, 10.0.100.0/22 is the best choice that meets the workstation requirement while minimizing unused addresses.
by Irene at Mar 18, 2026, 06:30 AM
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