Determining the Inter-Site Topology Generator (ISTG) of a Site in the Active Directory (224599)

SUMMARY

Windows 2000 Domain controllers each create Active Directory Replication connection objects representing inbound replication from intra-site replication partners. For inter-site replication, one domain controller per site has the responsibility of evaluating the inter-site replication topology and creating Active Directory Replication Connection objects for appropriate bridgehead servers within its site. The domain controller in each site that owns this role is referred to as the Inter-Site Topology Generator (ISTG).

For additional information about the role of the Inter-Site Topology Generator, please see the following article in the Microsoft Knowledge Base:

224815 The Role of the Inter-Site Topology Generator in Active Directory Replication

MORE INFORMATION

Using the tools LDP.EXE and Active Directory Replication Monitor from the Windows 2000 Resource Kit, the administrator can determine which domain controller in each site currently holds this role. It is important to note that because each domain controller tracks the ISTG owner by reading an attribute in the Active Directory, during the transition of this role from one domain controller to another, focusing these tools on different domain controllers may produce a different result. As replication occurs and every domain controller receives the attribute change defining the ISTG owner, each domain controller will discover the change.

Using LDP.EXE from the Windows 2000 Resource Kit

Using LDP.EXE, search the Configuration Naming Context (a partition of the Active Directory containing objects that include settings for each domain controller in the enterprise) with the following criteria:
Base DN: CN=Sites,CN=Configuration,DC=RootDomainName,DC=Com
Filter : (cn=NTDS Site Settings)
Scope: Subtree
Attributes: interSiteTopologyGenerator
replacing RootDomainName with the name of the first domain installed in the enterprise (forest). This domain is known as the root domain.
In the search results, locate the entry which represents the appropriate server that the ISTG is being determined for. The "interSiteTopologyGenerator" attribute should also be present and contain the Distinguished Name (DN) of the server that currently owns the role. For example:
***Searching...
ldap_search_s(ld, "cn=sites,cn=configuration,dc=mydomain,dc=com", 2, "(cn=NTDS Site Settings)", attrList, 0, &msg)
Result <0>: (null)
Matched DNs:
Getting 1 entries:
>> Dn: CN=NTDS Site Settings,CN='site-name',CN=Sites,CN=Configuration,DC=mydomain,DC=com
1> interSiteTopologyGenerator: CN=NTDS Settings,CN=W2KNC-DC,N=Servers,CN=Charlotte,CN=Sites,CN=Configuration,DC=mydomain,DC=com;
The Distinguished Name (DN) of the server that owns the role is identified as the data of the attribute. In this example, it is the server named "W2KNC-DC" in the "Charlotte" Site.

Using Active Directory Replication Monitor from the Windows 2000 Resource Kit

If the Windows 2000 Resource Kit is not already installed, perform this step before proceeding. For more information on the usage of Active Directory Replication Monitor, please refer to the Windows 2000 Resource Kit Documentation.
Open Active Directory Replication Monitor and use the Add Site/Server Wizard from the Edit menu to add the server that you are identifying the Server GUID for.
After Active Directory Replication Monitor has enumerated the naming contexts and replication partners, right-click the name of the server just below the site name.
Select Generate Status Report and supply a file name to save the results of the report to.
After Active Directory Replication Monitor displays that the report is complete, open the resulting report file and locate the "Enterprise Data" section of the report. For each site listed, the Inter-Site Topology Generator will be recorded. If no domain controllers exist for the site, no ISTG will be recorded. For example:
Site Name: Default-First-Site-Name
Site Topology Generator: CN=NTDS Settings,CN=W2KNC-DC,CN=Servers,CN=Charlotte,CN=Sites,CN=Configuration,DC=mydomain,DC=com