UPS service Issue: While configuring the UPS, getting No permission of 'Replicating Directory Changes' at the parent domain(domain user name) for domain user name

Solutions:

Permission of 'Replicating Directory Changes'  to parent domain for UPS user.

Eg: Here am using system account for UPS configuration. If is there any more than one node in Active Directory(Parent and child) we need to provide permissions for system account in both nodes in AD.