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Missing replication connection after promoting DC running windows 2008

    Question

  • Hi,

    I wonder if someone here can help me.

    I have just introduced a new domain controller running Windows Server 2008.

    Before that I run adprep /forestprep and adprep /domainprep gpprep on my DC schema and infrastructure master

    Everything seeems to be working fine except for one thing:

    I have 4 DCs, 3 Win2k3 and 1 Win2k8. Here are how the connections in AD Sites and Services looks like:

    DC,DC2 and DC3 are windows 2003
    DC4 is windows 2008

    DC1 have replication connection to DC2 and DC3
    DC2 have replication connection to DC1, DC3 and DC4
    DC3 have replication connection to DC2, DC3 and DC4
    DC4 have replication connection to DC2 and DC3

    As you can see there is a miising connection between DC1 and DC4, I hav etried to created manually but with no luck.

    On DC4 I found the following event viewer information message:

    To improve the replication load of Active Directory Domain Services, a replication connection from the following source directory service to the local directory service was deleted.
     
    Source directory service:
    CN=NTDS Settings,CN=DC01,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=****,DC=***,DC=UK
    Local directory service:
    CN=NTDS Settings,CN=DC04,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=****,DC=***,DC=UK
     
    Additional Data
    Reason Code:
    0x0
    Deletion Point Internal ID:
    f07024f


    I didn't delete the connection so that was automatic.

    It looks like windows 2008 regards that connection as redundant.

    Anybody knows what going on here?

    Thanks


    Monday, November 17, 2008 3:51 PM

Answers

  •  

    Hi,

     

    The KCC is designed to produce a replication topology that provides low replication latency, that adapts to failures. It will create, modify and delete replication connections according different environments.

     

    As Swaminathan said, the connection was deleted by KCC. This behave is normal. KCC will generate replication topology dynamically based on your actual Network load, speed and other factors. It will delete older replication connections to reduce Network load and improve performance.

     

    Connections between domain controllers in the same site are always arranged in a ring by KCC, with possible additional connections to reduce latency. To reduce network traffic, connections would not be created for every two DCs if all update could be replicated in time.

     

    From your existing replication connection, if there is any update occurred in DC1, the update will be replicated to DC4 by DC2 or DC3. It works properly.

     

    Thanks

    Tuesday, November 18, 2008 7:15 AM
    Moderator

All replies

  • The connection is deleted by KCC (Knowledge Consistency Checker). Read the following topic for more info: How Active Directory Replication Topology Works.
    http://technet.microsoft.com/en-us/library/cc755994.aspx
    Swami
    Monday, November 17, 2008 6:38 PM
  •  

    Hi,

     

    The KCC is designed to produce a replication topology that provides low replication latency, that adapts to failures. It will create, modify and delete replication connections according different environments.

     

    As Swaminathan said, the connection was deleted by KCC. This behave is normal. KCC will generate replication topology dynamically based on your actual Network load, speed and other factors. It will delete older replication connections to reduce Network load and improve performance.

     

    Connections between domain controllers in the same site are always arranged in a ring by KCC, with possible additional connections to reduce latency. To reduce network traffic, connections would not be created for every two DCs if all update could be replicated in time.

     

    From your existing replication connection, if there is any update occurred in DC1, the update will be replicated to DC4 by DC2 or DC3. It works properly.

     

    Thanks

    Tuesday, November 18, 2008 7:15 AM
    Moderator