Classful Addressing

Question 1

IPv4 address is how many bits long?

Answer 1

32 bits

Question 2

IPv4 address is how many octets long?

Answer 2

4 octets

Question 3

IPv4 address is how many bytes long?

Answer 3

4 bytes (1 byte = 8 bits)

Question 4

How long is the network portion for a Class A address?

Answer 4

1 octet (1 byte or 8 bits)

Question 5

How long is the network portion for a Class B address?

Answer 5

2 octets (2 bytes or 16 bits)

Question 6

How long is the network portion for a Class C address?

Answer 6

3 octets (3 bytes or 24 bits)

Question 7

What is the leading bit(s) for a Class A address?

Answer 7

Leftmost bit is 0

Question 8

What is the leading bit(s) for a Class B address?

Answer 8

Leftmost 2 bits are 10

Question 9

What is the leading bit(s) for a Class C address?

Answer 9

Leftmost 3 bits are 110

Question 10

How many Class A network addresses are there?

Answer 10

128
Calculation: 2**7 = 128
(Note: First bit unusable; Assuming that all-zero network is allowed)

Question 11

How many Class A hosts addresses are there per network?

Answer 11

16,777,214

Calculation: (2**24) - 2 = 16,777,216 - 2 = 16,777,214

Question 12

How many Class B network addresses are there?

Answer 12

16,384
Calculation: 2**14 =16,384
(Note: First two bits unusable; Assuming that all-zero network is allowed)

Question 13

How many Class B hosts addresses are there per network?

Answer 13

65,534

Calculation: (2**16) - 2 = 65,536 - 2 = 65,534

Question 14

How many Class C network addresses are there?

Answer 14

2,097,152
Calculation: 2**21 =2,097,152
(Note: First three bits unusable; Assuming that all-zero network is allowed)

Question 15

How many Class C hosts addresses are there per network?

Answer 15

254

Calculation: (2**8) - 2 = 256 - 2 = 254

Question 16

How many usable network bits in Class A?

Answer 16

7 bits
(Note: 8 - 1 reserved bit = 7)

Question 17

How many usable network bits in Class B?

Answer 17

14 bits 
(Note: 16 - 2 reserved bits = 14)

Question 18

How many usable network bits in Class C?

Answer 18

21 bits
(Note: 24 - 3 reserved bits = 21)

Question 19

What is the network address range for Class A?

Answer 19

1.0.0.0 - 126.0.0.0

Note: 0.0.0.0 and 127.0.0.0 are reserved

Question 20

What is the network address range for Class B?

Answer 20

128.0.0.0 - 191.255.0.0

Question 21

What is the network address range for Class C?

Answer 21

192.0.0.0 - 223.255.255.0

Question 22

What is the private address range for Class A?

Answer 22

10.0.0.0 - 10.255.255.255

Note: 10.255.255.255 is a broadcast address

Question 23

What is the private address range for Class B?

Answer 23

172.16.0.0 - 172.31.255.255

Note: 172.31.255.255 is a broadcast address

Question 24

What is the private address range for Class C?

Answer 24

192.168.0.0 - 192.168.255.255

Note: 192.168.255.255 is a broadcast address