When database users are authenticated by a single directory service, all necessary TDGSS configuration can be done in the LDAP mechanism section of the TdgssUserConfigFile.xml.
When database users are authenticated in multiple directory services, you must create an <LdapConfig> section in the TdgssUserConfigFile.xml, and populate it with the needed subsections and properties, on each Teradata Vantage system served by the directories.
For general information, see Changing the TDGSS Configuration.