Configuring Azure AD Connect to use specific Domain Controller

Introduction

Microsoft Azure AD Connect (AAD Connect) tool replicates your on-premises Active Directory with Office 365. Configuring Azure AD Connect to use specific domain controller can help expedite the process of replicating the changes to Office 365. I have seen scenario’s where on-premises Active Directory changes have not been replicated to Office 365 after 30minutes and Azure AD Connect shows a successful Delta Sync status in MIIS client. The fact why it happens is because Azure AD Connect is replicating the changes to Office 365 from a domain controller which doesn’t have your latest updates.

How Azure AD Connect locate a Domain Controller?

When you deploy Azure AD Connect tool in Active Directory forest, Azure AD Connect leverage DNS to locate a domain controller. Once Azure AD connect has a domain controller information, it connects with the same domain controller every time until the domain controller is not reachable and than Azure AD Connect tries to connect to another domain controller.

Why we need to Configure Azure AD Connect to use specific Domain Controller?

Configuring Azure AD Connect to use specific domain controller is required when you are implementing directory synchronization with Office 35 for multi-site active directory infrastructure where users are in multiple active directory sites across the globe.If you are modifying active directory changes and need to have them replicated to Office 365 quickly than we have 2 options, option 1 is to modify the changes to the domain controller from where Azure AD Connect is replicating the changes to Office 365. Downside of option 1 is that, you have to check the domain controller information from where the changes were being replicated during the last sync cycle. Option 2 is to configure the AAD Connect tool to use specific domain controllers. It’s much easy to configure the list of domain controllers in directory sync tool than to wait for replication changes to happen across active directory sites.

Configuring Azure AD Connect to use specific Domain Controller

Once the directory synchronization tool is installed. Follow the steps mentioned below to configure the list of domain controllers to which Azure AD Connect tool will connect.

  • Login to Azure AD Connect server and run the miis client

if you have installed the tool on default location, than Miis client can be located from C:\Program Files\Microsoft Azure AD Sync\UIShell

Configuring Azure AD Connect to use specific Domain Controller

  • Navigate to connectors and go to the properties of your connector

Configuring Azure AD Connect to use specific Domain Controller

  • In properties windows, select Configure Directory Partition and click on Configure to define your prefer domain controllers

Configuring Azure AD Connect to use specific Domain Controller

  • Enter the FQDN of your preferred domain controllers and click on Add

Configuring Azure AD Connect to use specific Domain Controller

 

  • Once you have defined the preferred domain controllers, make sure you have mark the checkbox next to Only use preferred Domain Controllers

Configuring Azure AD Connect to use specific Domain Controller

  • Click OK button to complete the configuration of preferred domain controller in Azure AD Connect tool

Azure AD connect tool is now configured to use preferred domain controllers only. Azure AD Connect will always check the preferred domain controllers for any modification in Active Directory to replicate with Office 365. More information on Azure AD Connect tool can be found here