How to determine the sum route for given IP networks:
This article shows step-by-step how to determine a sum route for the following networks:
The aim is to find a single route that covers all of the above networks.
In order to identify the common bits, the network addresses must be presented in binary format:
| Network | Binary address (first 24 bits) |
|---|---|
| 10.10.168.0/23 | 00001010.00001010.10101000.00000000 |
| 10.10.170.0/23 | 00001010.00001010.10101010.00000000 |
| 10.10.172.0/23 | 00001010.00001010.10101100.00000000 |
| 10.10.174.0/24 | 00001010.00001010.10101110.00000000 |
Analysing the addresses above, we notice that the first 21 bits are common to all four networks.
Based on the shared bits, the best summary route covering all the given networks is:
10.10.168.0/21
This summary route covers the address range 10.10.168.0 to 10.10.175.255, which covers all the networks listed.
The route 10.10.168.0/21 covers the following subnets:
This allows us to confirm that the route 10.10.168.0/21 is the correct summary route for the specified networks.
If you want to better understand the route aggregation process, I recommend watching the video below:
This step-by-step video explains how to find a route summation, which may be helpful in exploring the topic further.