IP address calculation rule

IP address calculation rule

How to get Block size of given subnet mask

Subnet mask -256

Example:-   Given subnet mask = 255.255.255.248

Block Size will be  256 – 248 = 8

Usable IPs will be    8 – 2 = 6

Because first IP will be used for Network ID and Last IP will be used for Broadcast

How to get Block Size of given Bit

32 Bit – given Bit = x bit     Block Size   (2) the power     x bit

For Example:-  Given IP address range is 8.12.172.100 /29

Block Size will be    32 bit – 29 bit = Block size 3 bit              (2)3 = 2x2x2 = 8

So there will be 8 subnets    To get first IP subnet Block 256 / Block Size

For Above Block Example    256 /8 = 32

1-      Block   0 – 31

2-      Block   32- 63

3-      Block  64 –95

4-       Block 96 – 127

5-      Block 128 – 159

6-      Block 160 – 191

7-      Block 192 – 223

8-      Block 224 – 256