IP Address Classes

Question 1

Class A: Address Range

Answer 1

1.0.0.0 to 126.0.0.0/8

126 networks
16,777,214 hosts per network

Question 2

Class A: Reserved Addresses

Answer 2

0. 0.0.0/8 - reserved; signifies “this network”
1. 0.0.1 to 0.255.255.255 are not valid host addresses
2. 0.0.0/8 - reserved for loopback address
3. 0.0.1 to 127.255.255.255 are not valid host addresses

Question 3

Class B: Address Range

Answer 3

128.0.0.0 to 191.255.0.0/16

16,384 networks
65,534 hosts per network

Question 4

Class C: Address Range

Answer 4

192.0.0.0 to 223.255.255.0/24

2,097,152 networks
254 hosts per network

Question 5

Class D Addresses

Answer 5

Reserved for IP multicast addresses
Not allocated to hosts; no default subnet

Address Range
224.0.0.0 to 239.255.255.255

Question 6

Class E Addresses

Answer 6

Experimental & reserved for future use

Not allocated to hosts; no default subnet

Address Range
240.0.0.0 to 255.255.255.255

Question 7

RFC 1918 (Private IP Addresses)

Answer 7

Class A: 10.0.0.0 to 10.255.255.255
10.0.0.0/8

Class B: 172.16.0.0 to 172.31.255.255
172.16.0.0/12

Class C: 192.168.0.0 to 192.168.255.255
192.168.0.0/16