This blog describes the problem statement and resolution; i.e., how to handle multi-domain issues during SharePoint Migration.
This is a quite interesting and common scenario which we face in almost all migration projects; i.e., On-Premises to On-Premises or On- Premises to Online. SharePoint Migration projects easily enter into escalation mode due to multi domain users after application migration.
Somehow the application team tries to convince the business user to adapt or change the User Name with a NEW domain. This is something no business user is ready to accept.
This scenario is illustrated in below diagram,
Problem Statement
Before Migration, the project was using Domain OLD.com and application URL like https://sharepoint.old.com where the user also has their login id like <<Domian>>\<<USerName>> old\user etc.
The business wants to migrate the application to a different domain; i.e., On Premises or Online.
Take a new domain like NEW.com and application URLs like https://sharepoint.new.com
Users who are part of the NEW domain can easily recognize by controlling and starting to use the application but some users are still part of an old domain.
As our new migrated application is hosted into a new domain, old domain users don’t recognize new domain applications.
Below are the ways to resolve the issue,
Option 1
If both domains have TWO WAY TRUST. No configuration required. the user can be added as <<OLDDomain>>\<UserID>; instead of only user name.
Option 2
If both domains have ONE WAY TRUST. Only people picker control configuration need to do using PowerShell. It will help control the application to recognize the user.
Option 3
If both domains don't have TRUST process, user Profile Synchronization needs to perform. It will help control the application to recognize the user.