Magic Number Subnetting

What is the optimal subnet mask to support at least 40 devices per subnet?

• 255.255.255.0

• 255.255.255.128

• 255.255.255.192

• 255.255.255.224

How many usable host addresses are available in a subnet with 6 host bits?

• 30

• 62

• 126

• 254

How is the "magic number" calculated in the subnetting process?

• Subtract the interesting octet from 255.

• Add the interesting octet to 256.

• Subtract the interesting octet from 256.

• Multiply the interesting octet by 2.

What is the subnet ID for the IP address 165.245.77.14 with a subnet mask of 255.255.240.0?

• 165.245.77.0

• 165.245.64.0

• 165.245.79.0

• 165.245.0.0

What is the subnet ID for the IP address 10.180.122.244 with a subnet mask of 255.248.0.0?

• 10.180.0.0

• 10.176.0.0

• 10.122.0.0

• 10.248.0.0