The address of a class B host is to be split into subnets with a 6-bit subnet…
2007
The address of a class B host is to be split into subnets with a 6-bit subnet number. What is the maximum number of subnets and the maximum number of hosts in each subnet?
- A.
62 subnets and 262142 hosts.
- B.
64 subnets and 262142 hosts.
- C.
62 subnets and 1022 hosts.
- D.
64 subnets and 1024 hosts.
Attempted by 218 students.
Show answer & explanation
Correct answer: C
Answer: 62 subnets and 1022 hosts per subnet.
Start: A Class B address has a /16 default mask, so there are 16 host bits.
Subnetting: Using 6 bits for the subnet gives 2^6 = 64 possible bit patterns. Under the traditional rule that excludes the all-zeros and all-ones subnet, usable subnets = 64 - 2 = 62.
Hosts per subnet: Remaining host bits = 16 - 6 = 10. Total addresses per subnet = 2^10 = 1024, and usable hosts = 1024 - 2 = 1022 (subtract network and broadcast addresses).
Note: Some modern practices allow using subnet-zero and the all-ones subnet, which would give 64 usable subnets. This question uses the traditional subtraction of 2, so the answer is 62 subnets and 1022 hosts.