none
Interforest Trust Funcional Level Pre-requisites RRS feed

  • Question

  • Hello,

    My company runs an AD with Forest and Domain Functional Level set at Windows 2012 DataCentre R2.
    We want to form an inter-forest trust with an external company and their FFL and DFL are both Windows 2008.

    Before establishing an inter-forest trust, this external company would like to upgrade to Windows 2016.
    If that is the case, in order to build the inter-forest trust and upgrading their AD at the same time, does it mean that when they upgrade, they have to set their FFL to Windows 2012 while DFL can be set at Windows 2016?

    Is it a pre-requisite that both our FFLs must be equal before an inter-forest trust can be established?

    Thanks in advance.

    Tuesday, September 24, 2019 12:51 PM

Answers

  • HI

    Is it a pre-requisite that both our FFLs must be equal before an inter-forest trust can be established?
    No. but if you want 2 forests keep forest function level the same ,you can set FFLs to be equal before an inter-forest trust can be established.

    Does it mean that when they upgrade, They have to set their FFL to Windows 2012 while DFL can be set at Windows 2016?
    No,in general , FEL<=DFL<=OS version .so we can refer 《
    Forest and Domain Functional Levels》 to decide which feature of FFL and which feature of DFL do we need now in our external company.

    Forest and Domain Functional Levels
    https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/active-directory-functional-levels
    Checklist: Creating a forest trust
    https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2003/cc756852(v=ws.10)?redirectedfrom=MSDN
    Domain and Forest Functional Levels – Overview
    https://activedirectoryfaq.com/2015/03/domain-and-forest-functional-levels-overview/
    Active Directory Forest Trust: Attention Points
    https://social.technet.microsoft.com/wiki/contents/articles/50969.active-directory-forest-trust-attention-points.aspx

    Best Regards
    Andy YOU
    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.



    Wednesday, September 25, 2019 9:53 AM
    Moderator