Last Updated on November 15, 2023 by InfraExam
What subnet mask is needed if an IPv4 network has 40 devices that need IP addresses and address space is not to be wasted?
|Explanation & Hint:
To determine the subnet mask needed for a network with 40 devices, you need to calculate the subnet size that can accommodate at least 40 hosts. Remember that in a subnet, two IP addresses are reserved: one for the network address and one for the broadcast address. So, you need a subnet with at least 42 addresses.
Here’s how the subnet masks correspond to the number of addresses they provide:
The smallest subnet mask that can accommodate at least 42 addresses is 255.255.255.192, which is a /26 subnet mask. This will allow for 62 usable IP addresses, which is more than enough for 40 devices without wasting too much address space.