A network administrator wants to have the same network mask for all networks at a particular small site. The site has the following networks and number of devices:
IP phones – 22 addresses
PCs – 20 addresses needed
Printers – 2 addresses needed
Scanners – 2 addresses needed
The network administrator has deemed that 192.168.10.0/24 is to be the network used at this site. Which single subnet mask would make the most efficient use of the available addresses to use for the four subnetworks?
If the same mask is to be used, then the network with the most hosts must be examined for the number of hosts, which in this case is 22 hosts. Thus, 5 host bits are needed. The /27 or 255.255.255.224 subnet mask would be appropriate to use for these networks.