Network Security » Classful Addressing
Number of Blocks in class C are –

A. 27
B. 28
C. 214
D. 29

Explanation: Number of Blocks in class A are 27.

A router receives a packet with the destination address 132.7.21.84. Find the network address of the packet.

A. 1.32.7
B. 132.7
C. 13.27
D. 21.84

Explanation: 132 is between 128 and 191, so it is Class B address i.e. n=16-bit. Therefore, Network address 132.7 Host address 21.84.

Each block in class B contains __________ addresses.

A. 28
B. 224
C. 214
D. 216

Explanation: Each block in class B contains 216 addresses.

Number of Blocks in class B are –

A. 212
B. 216
C. 214
D. 218

Explanation: Number of Blocks in class B are 214.

Percent of addresses occupied by Class D?

A. 0.5
B. 0.25
C. 0.0625
D. 0.125

Explanation: Class D has 228 addresses in total.

Which of the following does not have a Net ID and Host ID?

A. Class a
B. Class b
C. Class c
D. Class d

Explanation: Class D is the multicast address class. It does not have Net ID and Host ID fields.

Which Class is reserved for future use?

A. A
B. B
C. D
D. None of the mentioned

Explanation: Class E is reserved for future use.

What is the size of the Host ID in Class C?

A. 24 bits
B. 16 bits
C. 8 bits
D. 14 bits

Explanation: The size of the Host ID in Class C is 8 bits.

Address of the block is –

A. 214
B. 216
C. 28
D. 224

Explanation: Since 180 is between 128 and 191, it is class B address n=16. N = 2(32-n) = 216 = 65,536.

First Address is –

A. 180.8.0.0
B. 180.7.64.0
C. 180.8.1.256
D. 180.12.0.0

Explanation: Keep the leftmost 16 bits and set the rightmost 16 bits all to 0s. First address = 180.8.0.0, in which 16 is the value of n.