You are the network administrator for your company. You have been assigned the task of configuring an
appropriate IP addressing scheme in the network.
Assuming that the network address is 192.16.100.0/28, what will be the number of hosts per network in this
scenario?

A.
2

B.
6

C.
14

D.
30

Explanation:
In this scenario, there will be 14 hosts per network. The formula for calculating the number of hosts on a subnet
is 2n – 2, where n is the number of host bits in the summary mask. The n can be calculated by subtracting host
bits from the total number of bits in a subnet mask (32). In this case, n would be 32 – 28 = 4. Therefore, the
formula to calculate the number of bits in this scenario would be:
2(32 -28) – 2 = 24 – 2 = 14 hosts
You always subtract 2 from 2n because the all-zero-bit address is reserved for the network address (called the
network ID) and the all-one-bit address is reserved for the broadcast address.
The 192.16.100.0/28 network address would not have 30 hosts per network. The 192.16.100.0/27 network
address would actually yield 30 hosts per network. In this case, n would be 32 – 27 = 5, so the number of host
bits in the subnet mask would be 32 – 2, which is equal to 30.
The 192.16.100.0/28 network address would not have 6 hosts per network. The 192.16.100.0/29 network
address would yield 6 hosts per network. In this case, n would be 32 – 29 = 3, so the number of host bits in the
subnet mask would be 8 – 2, which is equal to 6.
The 192.16.100.0/28 network address would not have 2 hosts per network. The 192.16.100.0/30 network
address would yield 2 hosts per network. In this case, n would be 32 – 30 = 2, so the number of host bits in the
subnet mask would be 4 – 2, which is equal to 2.Objective:
Network Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot IPv4 addressing and subnetting

Cisco > Technology Support > IP > IP Routing > Design Technotes > IP Addressing and Subnetting for New
Users > Document ID: 13788 > Understanding IP Addresses