The process of taking a range of IP addresses and advertising them in one address block is known as summarization or route summarization. It allows routing protocol to advertise to many networks as one address. The purpose of this is to reduce the size of the routing table on the router to save memory.

There are two types of summarization

Automatic Summarization 2) Manually

Example

192.168.1.0/24

192.168.2.0/24

192.168.3.0/24

192.168.4.0/24

192.168.5.0/24 (These are IP range, we have to find one address of advertising these range of IP address)

192 168 1 0

192 168 2 0

192 168 3 0

192 168 4 0

192 168 5 0

—————————————————————

8 8 ? 0

You have to find out 3^rd octet. We can solve this in binary format.

2⁷ 2⁶ 2⁵ 2⁴ 2³ 2² 2¹ 2⁰

1 0 0 0 0 0 0 0 1

2 0 0 0 0 0 0 1 0

3 0 0 0 0 0 0 1 1

4 0 0 0 0 0 1 0 0

5 0 0 0 0 0 1 0 1

1 1 1 1 1 0 0 0

(We did AND operation) all same values is 1’s and different values is 0’s

2⁷ 2⁶ 2⁵ 2⁴ 2³ 2² 2¹ 2⁰

1 1 1 1 1 0 0 0

128+ 64+ 32+ 16+ 8

=248

192 168 1 0

192 168 2 0

192 168 3 0

192 168 4 0

192 168 5 0

—————————————————————

8 8 5 0

So the address is 192.168.248.0. and CIDR value is 21 because we got 5 on a bit after solving the 3^rd octet and we have 16 on bits from the 1^st and 2^nd octet.

Download Free CCNA Android Apps from Playstore

Check Out the Headphones – 50% to 70% Off

Check Out the Earbuds – 50% to 70% Off