Recipe 11.4 Creating a Subnet

11.4.1 Problem

You want to create a subnet.

11.4.2 Solution Using a graphical user interface
  1. Open the Active Directory Sites and Services snap-in.

  2. Right-click on the Subnets container and select New Subnet.

  3. Enter the Address and Mask and then select which site the subnet is part of.

  4. Click OK. Using a command-line interface

Create an LDIF file called create_subnet.ldf with the following contents:

dn: cn=<Subnet>,cn=subnets,cn=sites,cn=configuration,<ForestRootDN>
changetype: add
objectclass: subnet
siteObject: cn=<SiteName>,cn=sites,cn=configuration,<ForestRootDN>

then run the following command:

> ldifde -v -i -f create_subnet.ldf Using VBScript
' This code creates a subnet object and associates it with a site.
strSubnet = "<Subnet>"     ' e.g.
strSite   = "<SiteName>"   ' e.g. Dallas
' ------ END CONFIGURATION ---------

set objRootDSE = GetObject("LDAP://RootDSE")
set objSubnetsCont = GetObject("LDAP://cn=subnets,cn=sites," & _
                               objRootDSE.Get("configurationNamingContext") )
set objSubnet = objSubnetsCont.Create("subnet", "cn=" & strSubnet)
objSubnet.Put "siteObject", "cn=" & strSite & ",cn=sites," & _

WScript.Echo "Successfully created subnet " & strSubnet

11.4.3 Discussion

Subnet objects reside in the Subnets container (e.g., cn=subnets,cn=sites,cn=configuration,dc=rallencorp,dc=com) in the CNC. The relative distinguished name (RDN) of the subnet should be the subnet address and bit-mask combination (e.g., The other important attribute to set is siteObject, which should contain the DN of the site that the subnet is associated with.

11.4.4 See Also

MS KB 323349 (HOW TO: Configure Subnets in Windows Server 2003 Active Directory)

    Chapter 3. Domain Controllers, Global Catalogs, and FSMOs
    Chapter 6. Users
    Appendix A. Tool List