Introduction to Administering AD LDS Sites

Applies To: Windows Server 2008


Active Directory Lightweight Directory Services (AD LDS) uses topology information, which is stored as site objects and site link objects in the configuration directory partition, to build the most efficient replication topology for a configuration set. You can use sites in AD LDS to represent the physical structure, or topology, of your network.

Site objects

You can create a site object in AD LDS to represent each area of your network (typically, a building or a group of buildings) in which all computers are connected by high-speed bandwidth. You can then move the directory objects of AD LDS instances that are located in each area of the network into the corresponding site object. By default, the directory objects of each AD LDS instance that you create belong to a single default site (CN=Default-First-Site-Name,CN=Sites,CN=Configuration,CN={GUID}).

For information about establishing single or multiple sites, see Administering AD LDS Replication, Sites, and Configuration Sets.

You can use site link objects in the directory to represent low-speed bandwidth connections between the sites on your network. Site link objects help you tune replication on your network; you can use them to determine the relative cost of replication across each site link. By default, the default site (CN=Default-First-Site-Name) belongs to the default site link object (CN=DEFAULTIPSITELINK,CN=IP,CN=Inter-Site Transports,CN=Sites,CN=Configuration,CN={GUID} ). You can add new sites that you create to the default site link object. You can also create additional site link objects to represent each of the actual site links on your network.

Each site link object in the directory has an associated cost. You can edit the cost attribute on a site link object to specify the relative cost of replication across that site link. AD LDS takes into consideration site link costs when it builds the replication topology. AD LDS considers a site link with a higher cost to be less desirable than a site link with a lower cost. When multiple paths for replication are available, AD LDS prefers the site link with the lower cost.

For more information about how sites affect replication, see Introduction to Administering AD LDS Sites and Replication.