DC Locator Process

This is mainly as a reminder for me where to find this information.  Jorge has a great write up describing the process that a client uses to find the closest DC.  Two things that interest me are some commands that can be used to determine both site and the closest DC:

This command will get the AD site:

  • nltest /dsgetsite

This command will determine the closest DC:

  • nltest /dsgetdc:<FQDN Domain>

This is another interesting note:

Make sure you also see MS-KBQ247811, as there it mentions: "After the client locates a domain controller, the domain controller entry is cached. If the domain controller is not in the optimal site, the client flushes the cache after fifteen minutes and discards the cache entry. It then attempts to find an optimal domain controller in the same site as the client."

If you are using DFS shares, it is possible to find all of the DFS referrals (as well as the referrals you receive for the Sysvol and Netlogon DFS shares):