Summary Static Route

[amh4y0001]

Hi,

How to write / calculate the summary route? See below example, here I can understand how the summary route was determined.

[Milos Megis · Accepted solution]

Hi,
let write 2nd octet in binary form.

172.20.0.0/16 - 172.0001 0100.0.0/16
172.21.0.0/16 - 172.0001 0101.0.0/16
172.22.0.0/16 - 172.0001 0110.0.0/16
172.23.0.0/16 - 172.0001 0111.0.0/16

You see that first 6 bits in 2nd octet are same. So you can write summary route (same bits from left):
172.0001 0100.0.0 (rest are zero) and length of subnet mask is as long as bits are same, so in this example it is 14 bits (8 bits from 1st octet and 6 bits from 2nd octet).
Summary route in decimal form is: 172.20.0.0/14

I hope that this help you.

[amh4y0001]

Hi,

Thanks for reply and it helped.