Which of the following IP ranges is considered private for typical enterprise networks?

• A. 203.0.113.0/24
• B. 10.0.0.0/8
• C. 172.31.0.0/16
• D. 192.168.0.0/16

Answer: (B)

Private IPv4 addresses are reserved for internal networks and are not routable on the public Internet. The range 10.0.0.0/8 is the largest of these private blocks, spanning from 10.0.0.0 to 10.255.255.255, and it is widely used in enterprises because it provides a huge pool of addresses that can be divided into many subnets without quickly running out of space. This makes it easy to design scalable internal networks and still use NAT at the network edge to reach external resources.

The other option, 203.0.113.0/24, is reserved for documentation and examples and isn’t intended for real network use, so it’s not used as a private internal range. While there are other private ranges (such as 172.16.0.0/12 or 192.168.0.0/16), the most typical choice for large enterprise networks is 10.0.0.0/8 because of its size and simplicity.