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User accounts have been involved in a domain migration. If a domain migration has been done, a user will be given a new principle SID in relation to the domain he or she has been migrated to while maintaining the old SID in the sIDHistory attribute. If the administrator migrated the previous SIDs, the sIDHistory attribute will be populated with the old SID. Explain what happens if SID filtering is used.
What is The previous SID might have been kept to retain access to network resources in the old domain. This can cause problems because if the old SID is filtered off within a trust, the user will lose access to resources still pointing to the old SID.