After you define your sites, the next step in implementing the physical structure of Active Directory is to create subnets. A subnet is a division of a TCP/IP network, defined by the IP addresses and subnet masks of the computers (and other network devices). All computers belonging to a subnet share a common network ID.
Creating a subnet
Creating subnets occurs in two stages: 1) providing a name for the subnet in the form of network/bits masked identifier, and 2)
associating the subnet with a site. Here, we have broken down the process for you:
Open Active Directory Sites and Services from the Administrative Tools menu.
In the console tree, expand Sites.
Right-click Subnets, and then click New Subnet.
In the Name box, type the network/bits masked identifier.
Choose a site with which to associate this subnet, and then click OK.
To enact this process, perform the simulation below.
Select the Administrative Tools menu.
Open Active Directory Sites and Services.
In the next lesson, you willl define the parameters of your subnet's name.