DNS/AD Issue

I have a Root / Child domain model. We have 4 Sites. Root domain is only in Main Site and Child Domain is across all of the sites.

We have Windows 2003 R2 and Windows 2012 R2 Active Directory model.

Main Office:

Root domain have TWO windows 2012 R2 DC's and THREE Windows 2003 R2 DC's.

Child Domain have TWO WINDOWS 2012 R2 DC's and TWO Windows 2003 R2 DC's

Sites:

Each site have Windows 2003 R2 DC's

DNS:

All DC's are running DNS Service and 1 additional DNS Server is also available which holds secondary zones.

ISSUE:

I came across strange issue. While fixing my replication issues appearing on DCDIAG, I added Master Servers under additional DNS Server and my replication starts without any error. But automatically my _mcdcs.root.domain converts to ForestDNSZone and after 1 days root.domain and child.root.domain also change to ForestDNSZone. The evernt which logs this entry showing my user ID for this change but I didn't change this manually.

Please help me if there is any possibility of happening this automatically. Might be as I replicated and replication completed successfully this converts and as I did the replication the event for changing is generated with my ID.


Regards,

Faisal Kamal