The Server GUID (Globally Unique Identifier) is a reference point used in the Active Directory and DNS (Domain Name System) to locate a domain controller primarily for the purposes of replication. This GUID is automatically generated for each domain controller, is unique when created, and will not be duplicated. This article describes how to identify the Server GUID for a particular domain controller so that it may be used in troubleshooting problems.
This article outlines three ways of determining the server GUID using utilities in the Windows 2000 product and in the Windows 2000 Resource Kit. If Active Directory Replication Monitor or LDP.EXE are used, it is important to note that these utilities only return data known to the domain controller being queried. If the query results do not include the GUID for the requested server, this may be due to replication problems from other domain controllers in the enterprise. If such a failure occurs, these utilities should be focused against other domain controllers as alternate sources of information.
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
replacing RootDomainName with the name of the first domain installed in the enterprise (forest). This domain is known as the root domain.
Filter : (cn=NTDS Settings)
- In the search results, locate the entry which represents the appropriate server that the GUID is being determined for. The "objectGUID" attribute should also be present and look like the following:
The Server GUID is identified by the value associated with the objectGUID attribute (in this example, above in bold).
ldap_search_s(ld, "cn=sites,cn=configuration,dc=mydomain,dc=com", 2, "(cn=NTDS Settings)", attrList, 0, &msg)
Result <0>: (null)
Getting 1 entries:
>> Dn: CN=NTDS Settings,CN='server-name',CN=Servers,CN='site-name',CN=Sites,CN=Configuration,DC=mydomain,DC=com
1> objectGUID: e99e82d5-deed-11d2-b15c-00c04f5cb503;
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 filename to save the results of the report to.
- After Active Directory Replication Monitor indicates the report is complete, open the resulting report file and locate the "Enterprise Data" section of the report. Underneath each site, each server that resides in the site will also be listed. For each server, the Server GUID is identified beneath it. If the Server GUID is blank, this indicates that the domain controller has probably been demoted. For example:
Server GUID (used for DNS) : e99e82d5-deed-11d2-b15c-00c04f5cb503
Replication Database GUID : e98d5d92-deed-11d2-b14d-00c04f5cb503
Using the DNS Management MMC Snap-In
- Open the DNS Management MMC Snap-in located in the Administrative Tools menu. If a shortcut is not present, this will require starting a new MMC console and adding the snap-in manually.
- Set the focus of the DNS Management snap-in to a DNS server used by the domain controllers. Expand the server to display the nodes Forward Lookup Zones and Reverse Lookup Zones.
- Expand Forward Lookup Zones to display the zone which contains the domain where the domain controller resides. Traverse the hierarchy of the zone to display the domain that the server is a member of. Expand this node and double-click _msdcs.
- Each domain controller registers a CNAME record (Alias record) in this location identifying its Server GUID. In the right hand pane of the MMC console, locate the name of the server in the Data column and the Server GUID will be identified in the Name column.