The subnet mask for a particular network is 255.255.31.0. Which of the following pairs of IP addresses could belong to this network?
- A. 172.57.88.62 and 172.56.87.23
- B. 10.35.28.2 and 10.35.29.4
- C. 191.203.31.87 and 191.234.31.88
- D. 128.8.129.43 and 128.8.161.55
Answer: D. 128.8.129.43 and 128.8.161.55
Explanation: The mask 255.255.31.0 corresponds to binary 11111111.11111111.00011111.00000000. For two IPs to be on the same network, (IP AND Mask) must be identical. \nFor (d): \n129 (10000001) AND 31 (00011111) = 1. \n161 (10100001) AND 31 (00011111) = 1. \nBoth result in network 128.8.1.0.