To disable the Global Catalog search on a particular server, you must ensure that the LDAP server is not configured for ports 3268 or 3269. To disable global catalog search, follow the steps given below:
Log in to iManager and click LDAP > LDAP options.
Click the View LDAP Servers tab.
Click the server for which you want to disable global catalog search.
Click the Connections tab and edit the LDAP Interfaces field to remove the LDAP URL for ports 3268 and 3269.
Although this disables the Global Catalog search, it also impacts the functioning of the DSfW server. For example, by disabling Global Catalog search, operations such as searching of information in a DSfW forest will not work.