Which address range efficiently summarizes the routing table of the addresses for router Main?
A. 172.16.0.0./21 B. 172.16.0.0./20 C. 172.16.0.0./16 D. 172.16.0.0/18
Correct Answer: B
The 172.16.0.0./20 network is the best option as it includes all networks from 172.16.0.0 – 172.16.16.0 and does it more efficiently than the /16 and /18 subnets. The /21 subnet will not include all the other subnets in this one single summarized address.