IPv4 Summarization & Wildcard Mask

Summarization & Wildcard Mask

We can summarize the contiguous blocks of addresses in the power of two. Ex: 2, 4, 6, 8, etc. but we can’t summarize noncontiguous blocks network.

172.16.1.0/24

172.16.2.0/24

172.16.3.0/24

===

172.16.15.0/24

172  =   10101100

16    =   00010000

.00000001.00000000

.00000010.00000000

.00000011.00000000

.00001111.00000000

Network portion bits + similar bits. 8+8+4=20. 172.16.1.0/20 summarized.

Wild card mask:

Wild card mask is opposite to subnet mask. Define the network of host portion. In wild card on bits are called host portion and off bits are called network portion.

To find wild card mask, we minus known subnet mask from 255.255.255.255.

Ex: 255.255.255.255-255.255.255.192=0.0.0.63