A network administrator has been given a network of 172.16.85.0/21 and wants to know the usable range of IP addresses on that subnet. Which of the following indicates the correct IP address range?
A) 172.16.80.0-172.16.85.254
B) 172.16.80.0-172.16.88.255
C) 172.16.80.1-172.16.87.254
D) 172.16.80.1-172.16.85.255

Question

Quizplus · Accepted Answer

The /21 subnet mask means the subnet includes IPs from 172.16.80.0 to 172.16.87.255. The usable range excludes the network address (172.16.80.0) and the broadcast address (172.16.87.255), so it starts from 172.16.80.1 to 172.16.87.254.

A Network Administrator Has Been Given a Network of 172