IP address classes

Question 1

Class A

Public

Answer 1

1 - 126

255.0.0.0
/8

Question 2

Class B

Public

Answer 2

128 - 191

255.255.0.0
/16

Question 3

Class C

Public

Answer 3

192 - 223

255.255.255
/24

Question 4

Class D

Public

Answer 4

224 - 239

n/a n/a

Reserved for multicast groups.

Question 5

Class E

Public

Answer 5

240 - 254

Reserved for future use, or Research and Development Purposes.

Question 6

Class A

Private

Answer 6

10.0.0.0 - 10.255.255.255

Question 7

Class B

Private

Answer 7

172.16.0.0 - 172.31.255.255

Question 8

Class C

Private

Answer 8

192.168.0.0 - 192.168.255.255

Question 9

Loopback IP

Answer 9

127.0.0.1 - 127.255.255.255

• Most commonly used as 127.0.0.1
• Refers to the device itself and used for testing

Question 10

APIPA

Answer 10

169.254.0.0 - 169.254.255.255