Order upgrade forest and domain functional level

[thanhtien19]

We have root domain and child domain. To upgrade forest and domain functional level then need upgrade domain functional in child domain first ? After to domain functional in root domain ? And end is forest functional ?

[#2]

Raise the domain functional level first.

How to raise Active Directory domain and forest functional levels - Windows Server | Microsoft Docs

[#3]

Just checking if there's any progress or updates?

--please don't forget to upvote and Accept answers if the reply is helpful--

[#4]

So , should upgrade domain functional level first of child and to root domain ? and final is forest functional ?.thanks