Practice Test 1 | Google Cloud Certified Associate Cloud Engineer | Dumps | Mock Test

Correct Answer – D

IPv4 consists of 4 octets which sum up to 32 bit.

The formula to calculate the number of hosts is 2 power of n where n is the difference between 32 and subnet mask to be used. In this case, it will be 2 power  of 5 = 32 hosts. In each CIDR block, two IPs are reserved: one for the network address and another one for broadcast which leaves us with 30 usable IP addresses.

32 – 27 = 5

2 power of 5 = 32 total IP addresses

32 – 2 = 30 usable IP addresses

Option D is correct: A subnet mask of 27 gives you 30 usable IP addresses.

Option A is incorrect: 24 subnet mask gives you 254 addresses which is more than required.

Option B is incorrect: Subnet mask of 28 leaves you with only 14 usable IPs.

Option C is incorrect: A subnet mask of 18 provides you 16,382 IP addresses.

Reference:

https://www.computernetworkingnotes.com/ccna-study-guide/subnetting-tutorial-subnetting-explained-with-examples.html