Supernetting

Supernetting means to combine the different networks of class C and these networks must be in the sequence for supernetting. It is use to save IP addresses, to manage IP Addressing etc. Number of hosts will be increase after the supernetting is done. It is only for Intranet, not for Internet. Supernetting is CIDR  (Classless Inter Domain Routing) and also known as Summarization.

NOTE:

If we required 1000 hosts approximately and if we use class A or class B network, then most of the IP address will be wasted.

We have  class C networks :-

        200.100.50.0

        200.100.51.0

        200.100.52.0

        200.100.53.0

NOTE: If we combine all the available networks, then we will get 254 X 4 = 1016 host atleast.

Step for Supernetting :-

step1    Convert all networks into binary

                11001000.  01100100. 00110010 . 0

                11001000.  01100100. 00110011 . 0

                11001000.  01100100. 00110100 . 0

                11001000.  01100100. 00110101 . 0

step2    Select the common bits in all network or select the Supernet Block               

       

Step3   Consider the Supernet Block as one and the remaining bits as Zero

                11111111. 11111111 . 11111000. 00000000

Step4   Convert it into Decimal

                255. 255. 248. 0  /21

Step5   Use this number as subnet mask for all networks

/21(network bits)

32-21  ,  Then no. of hosts = 11   2¹¹ -2 = 2046 hosts

IP version 6