Microsoft Dynamics CRM uses the closest domain controller based on how your active directory topology is setup. This process usually works great and is the preferred method of running CRM. There is zero downtime if one domain controller fails, as CRM will use another domain controller automatically. However, there are cases when we need to temporarily tell CRM to only use a single domain controller, and in today’s blog, we will show you how to use PreferredDc to manually control which domain controller to use. Let’s get started!
You may be wondering why we would need this. Here are a few reasons:
- AD sites and services in dns are messed up.
- A domain controller is malfunctioning, but not down.
- A domain controller is up, but extremely slow.
- The AD environment has replication issues.
To force CRM to only use a single active directory domain controller:
1. Create the key: HKLM\Software\Microsoft\MSCRM
2. Create a new string value called PreferredDc
3. Specify the full dns name of the domain controller.
That’s it! The above key works in Microsoft Dynamics CRM 3.0/4.0/2011/2013/2015/2016 and will most likely work in CRM 2017.