Nokia Certified Network Associate (NCNA) — Question 6
Network 201.148.104.0/21 is subnetted using a /23 mask. How many subnets and host addresses per subnet will be obtained with this mask?
Answer options
- A. 2 subnets, 1022 hosts
- B. 4 subnets, 510 hosts
- C. 2 subnets, 2048 hosts
- D. 4 subnets, 512 hosts
Correct answer: B
Explanation
Using a /21 network and subnetting it with a /23 mask results in 2 additional bits for subnetting, allowing for 4 subnets. Each /23 subnet can accommodate 510 usable host addresses, as 2 addresses are reserved for network and broadcast purposes. The other options either miscalculate the number of subnets or the number of usable hosts.