Daily Learning: Computer Networks – Supernetting or Aggregation

In the routing table there is entry for all the sub networks present in a network. And as the network increase the size of the routing table also increase. For this the router combine multiple networks to form a bigger network.

Rules

1. IP addresses must be contiguous.
2. All network should be of same size(the size also should be 2^n).
3. The first network ID should be divisible by the size of the block(number of host).

200.1.0.0
200.1.1.0
200.1.2.0
200.1.3.0

Let’s see the IP address can form a supernet or not. Ans is yes they can. because-

1. All are contiguous.
2. All network of same size.
3. Total number of host is 4 * 2^8 then the first IP address is divisible.

Supernet Mask

We put all 1 in the place of Network ID and all 0 in the place of Host ID.

      200.1.00000000.00000000
      200.1.00000001.00000000
      200.1.00000010.00000000
      200.1.00000011.00000000
------------------------------------
    255.255.11111100.00000000   Mask

Supernet Mask is - 255.255.252.0