Subnetting is a set of techniques that you can use to efficiently allocate the address space of one or more unicast address prefixes among the subnets of an organization network.

To determine the subnet prefix of an IP version 4 (IPv4) address configuration in prefix length notation (w.x.y.z/n), retain the n high-order bits, set all the remaining bits to 0, and then convert the result to dotted decimal notation. To determine the subnet prefix of an IPv4 address configuration in subnet mask notation, perform a bit-wise logical AND between the IPv4 address and its subnet mask.

In addition to IPv4 addresses, Windows Server 2008 R2 also supports IP version 6 (IPv6) subnet prefixes. To create a subnet in the IPv6 address space, use either hexadecimal or decimal methods to enumerate the subnet address prefixes.

For more information, see Chapter 4 – Subnetting under TCP/IP Fundamentals for Microsoft Windows (

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