This document explains what will happen to Service Desk Contact information if LDAP integration is used and the AD Domain is changed. It also outlines the steps that need to be taken if that AD domain is changed.
If the AD Domain that is integrated with Service Desk is changed and the pdm_ldap_sync utility is run, all Contacts with LDAP attributes will be set to inactive. This is because their existing ldap_dn attribute does not match that of the new AD domain.
You need to update the value in the ldap_dn attribute in the Contact object (in the usp_contact table) with the new AD domain name before you run the pdm_ldap_sync utility. You can do this using the following steps:
pdm_extract usp_contact > contacts.txt
pdm_load -a -v -f contacts.txt