What is the most efficient summarization that R1 can use to advertise its networks to R2?
A.
172.1.0.0/22
B.
172.1.0.0/21
C.
172.1.4.0/22
D.
172.1.4.0/24
172.1.5.0/24
172.1.6.0/24
172.1.7.0/24
E.
172.1.4.0/25
172.1.4.128/25
172.1.5.0/24
172.1.6.0/24
172.1.7.0/24
Network 172.1.4.0/25 and network 172.1.4.128/25 can be grouped to a single network 172.1.4.0/24
Network 172.1.4.0/24 + Network 172.1.5.0/24 + Network 172.1.6.0/24 + Network 172.1.7.0/24 can be grouped to a single network 172.1.4.0/22 because we have all 4 subnetworks so we can move left 2 bits (2^2=4)
this is the wrong answer……….correct is 172.1.4.0/22
Please refer this ……….http://asecuritysite.com/ip/routesum