Assuming a subnet mask of 255.255.248.0, three of the following addresses are valid host addresses. Which are these addresses? (Choose three.)

Question:
Assuming a subnet mask of 255.255.248.0, three of the following addresses are valid host addresses. Which are these addresses? (Choose three.)

• 172.16.9.0
• 172.16.8.0
• 172.16.31.0
• 172.16.20.0

Explanation: From the subnet mask of 255.255.248.0 we learn that the increment is 8 therefore 172.16.8.0 is a network address which cannot be assigned to a host. Other network addresses are 172.16.16.0, 172.16.24.0, 172.16.32.0… Notice that 172.16.31.0 is a valid host address (which belongs to 172.16.24.0 to 172.16.31.255 subnet).

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