Which of the following network classes is identified by a subnet mask of 255.240.0.0?

The correct answer is B. Class B. The subnet mask 255.240.0.0 is equivalent to a /12 CIDR prefix (11111111.11110000.00000000.00000000 in binary). Because this mask extends beyond the first octet into the second octet, it falls within the Class B address space (128.0.0.0–191.255.255.255). Notably, 255.240.0.0 is…

Networking

Question

Options

AClass A
BClass B
CClass C
DClass D

How the community answered

(37 responses)

A
16% (6)
B
73% (27)
C
5% (2)
D
5% (2)

Explanation

The subnet mask 255.240.0.0 is equivalent to a /12 CIDR prefix (11111111.11110000.00000000.00000000 in binary). Because this mask extends beyond the first octet into the second octet, it falls within the Class B address space (128.0.0.0–191.255.255.255). Notably, 255.240.0.0 is precisely the mask for the IANA-defined private Class B block 172.16.0.0/12, which encompasses 172.16.0.0 through 172.31.255.255. Class A uses a /8 default mask (255.0.0.0), Class C uses /24 (255.255.255.0), and Class D is reserved for multicast with no standard subnet mask.

Topics

#subnet mask#TCP/IP classes#IP addressing#CIDR

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