An organization is granted the block 130.56.0.0/16. The administrator wants to…

Answer: The subnet mask is 255.255.255.192 (which is /26).

• You need 1024 subnets. Determine how many bits are required: 2^10 = 1024, so 10 bits are needed for subnetting.

• Starting prefix is /16. Add the 10 subnet bits: 16 + 10 = 26 → new prefix is /26.

• Convert /26 to dotted decimal: binary mask is 11111111.11111111.11111111.11000000 which equals 255.255.255.192.

• Each subnet size: 2^(32-26) = 64 addresses per subnet; usable hosts per subnet = 64 - 2 = 62.

Why the provided choices are incorrect:

• 130.255.255.255 is an IP address, not a subnet mask.

• 130.56.255.255 is an IP address (the broadcast address for 130.56.0.0/16), not a subnet mask.

• 130.56.0.255 is an IP address, not a subnet mask.

• 130.56.255.192 is an IP address (it may look like it contains the .192 octet), but the subnet mask should be written as 255.255.255.192.