Examples of Classless IP Addressing
Example: Consider a classless IP address is 184.108.40.206 / 28. Find out the range of IP Addresses in the CIDR block or classless block.
- 28 bits are used for network identification.
- Remaining 4 bits are used for host’s identification in the classless
Given CIDR IP Address may be represented as
00010101.00001011.00101000.00100011 / 28
- First IP Address = 00010100.00001010.00011110.00100000= 220.127.116.11
- Last IP Address = 00010100.00001010.00011110.00101111= 18.104.22.168
Put all Host bits to zero for first IP, and put all host bits to “1” for Last IP of Network.
Note: Direct broadcast IP address of a network is always the last IP of that Network.
Thus, Range of IP Addresses = [22.214.171.124 , 126.96.36.199]
Now Check all Three rules of CIRD block
- Rule 01: As all IP’s are contiguous ( 188.8.131.52 to 184.108.40.206). So Rule 1 is satisfied.
- Rule 02: Range ( 220.127.116.11 to 18.104.22.168) contains 16 IP’s which is the Power of 2. So Rule 2 is satisfied.
- Rule 03: According to third rule, First IP must be divisible by network size. As the Network Size is 24 and last 4 bits of first IP are Zero. So, it is divisible. Hence, Rule 3 is also satisfied.
As all 3 rules are valid, so, Classless block with 16 IP’s is Valid.