Abstract
This chapter describes the details of subnetting for both IPv4 and IPv6 address prefixes. Network administrators need to thoroughly understand subnetting techniques for both types of address prefixes to efficiently allocate and administer the unicast address spaces assigned and used on private intranets. This chapter includes detailed discussions of different subnetting techniques for IPv4 and IPv6 address prefixes. By using these techniques, you can determine subnetted address prefixes and, for IPv4, the range of usable IPv4 addresses for each new subnetted address prefix.