If you have a domain controller that runs Windows Server 2008 or newer, you can make it possible for client computers that run Windows Vista or newer or Windows Server 2008 or newer to locate domain controllers more efficiently by enabling the Try Next Closest Site Group Policy setting. This setting improves the Domain Controller Locator (DC Locator) by helping to streamline network traffic, especially in large enterprises that have many branch offices and sites.
AD – Enable Clients to Locate a Domain Controller in the Next Closest Site
This new setting can affect how you configure site link costs because it affects the order in which domain controllers are located. For enterprises that have many hub sites and branch offices, you can significantly reduce Active Directory traffic on the network by ensuring that clients fail over to the next closest hub site when they cannot find a domain controller in the closest hub site.
As a general best practice, you should simplify your site topology and site link costs as much as possible if you enable the Try Next Closest Site setting. In enterprises with many hub sites, this can simplify any plans that you make for handling situations in which clients in one site need to fail over to a domain controller in another site.
The Try Next Closest Site setting works in coordination with automatic site coverage. For example, if the next closest site has no domain controller, DC Locator tries to find the domain controller that performs automatic site coverage for that site.
By default, DC Locator does not consider any site that contains a read-only domain controller (RODC) when it determines the next closest site. In addition, when the client gets a response from a domain controller that runs a version earlier than Windows Server 2008, the DC Locator behavior is the same as when then setting is not enabled.
When the Try Next Closest Site Group Policy setting is enabled in this example, if a client computer in Site_B tries to locate a domain controller, it first tries to find a domain controller in its own Site_B. If none is available in Site_B, it tries to find a domain controller in Site_A.
In this blog post, we will talk about how clients discover domain controllers, and even how to connect to the nearest domain controller. We will also talk about what nearest means in this context.I was wondering how clients discover their domain controller, and what will happen if the DC located near the client is down.
The client will contact each DC in the list until it can connect to one of the domain controllers. The DC then validate the client IP and will return to him his assigned AD Site name. This information will be cached in the client memory. After that, it is matter of the client going to DNS, asking for domain controllers located in that AD site.
Saying that, and assuming you have your physical structure of active directory already in place, how can we make a client contact a domain controller in the nearest AD site if his local DC is down?In the figure below, suppose that the DC at site C is down, clients in site C will try to randomly pick domain controllers at site A or site B although Site A is the near site.
To help IT admins located the nearest domain controller, there is a GPO settings called Try next closest site. When DC at site C is down, clients will prefer domain controllers at site A. If it cannot connect to a domain controller in the nearest site, it will randomly pick any domain controller in the domain.
I tried to find the information on Internet - could we enable the "Try Next Closest Site" GPO setting ( -us/windows-server/identity/ad-ds/plan/enabling-clients-to-locate-the-next-closest-domain-controller) via Policy, which is applied to Windows 10 machines?
"This policy setting enables DC Locator to attempt to locate a DC in the nearest site based on the site link cost if a DC in same the site is not found. In scenarios with multiple sites, failing over to the try next closest site during DC Location streamlines network traffic more effectively. The DC Locator service is used by clients to find domain controllers for their Active Directory domain. The default behavior for DC Locator is to find a DC in the same site. If none are found in the same site, a DC in another site, which might be several site-hops away, could be returned by DC Locator. Site proximity between two sites is determined by the total site-link cost between them. A site is closer if it has a lower site link cost than another site with a higher site link cost.
A. By default, clients will try to find a DC in their local site; if no DC is found, clients will search for any DCs in the enterprise. You can configure Windows Vista and Windows Server 2008 to search for a DC in the next closest site if no local DC is available via a Group Policy change, as follows:1. Start the Group Policy Management Console (Start - Programs - Administrative Tools - Group Policy Management). 2. Expand the forest, expand the Domains, then select the domain. Right click "Default Domain Policy" and select Edit. 3. Navigate to Computer Configuration - Policies - Administrative Templates - System - Net Logon - DC Locator DNS Records. 4. Double click "Try Next Closest Site" and set to Enabled. Click OK.
I inherited a network that I noticed gpresult reporting GPOs are being applied from a server not on the LAN but from one across the WAN. The network is set to a hub and spoke and I just enabled try next closest Site. The DCs are a mix of SVR 2008 and 2008R2. The sites are connected by VLANs between Cisco ASAs.
This way the cmdLet Get-ADObject uses the next closest Domain Controller zu query the AD Domain. The DC has been selected with the cmdLet Get-ADDomaincontroller in consideration of the Active Directory Sites & Services Configuration.
The site information in which a domain controller is located is stored in the configuration directory partition in Active Directory, and this information is replicated to all domain controllers in the forest.. A domain controller can identify the site of a client by using the subnet object in the Sites container. Each subnet object has a siteObject property (attribute#34;) that links it to a site object; the value of the siteObject property is the distinguished name of the site object. This link enables a domain controller to identify clients that have an IP address in the specified subnet as being in the specified site.
In addition, the domain controller performs authentication, and a secure channel is set up. On subsequent location attempts, the lifetime of the cache and the lifetime of the secure channel are secondary to the location of a domain controller in the closest site.
Another way to prevent Active Directory clients to attach to a next-closest Domain Controller is placing multiple Domain Controller per Active Directory site. When the Domain Controller the Active Directory client is attached to becomes unavailable the client will still use a Domain Controller in its own Active Directory site. While this admittedly might not prevent against network outages, my experience is WAN connections are usually attached to the same active networking components. When the Domain Controllers become unavailable most of the times the WAN connection is unavailable too, preventing Active Directory clients to attach to Domain Controllers in other Active Directory sites.
Domain Controller Stickiness can be a real pain in the behind in multi-site Active Directory environments where clients attach to next-close Active Directory Domain Controllers. Microsoft acknowledged this problem and changed the DC Locator mechanism appropriately.
The following command finds the closest domain controller in thespecified domain ().By default, it will return the closest DC for the computernltest is being run from, but you can optionallyuse the /server option to target a remote host.You can also optionally specify the /site optionto find a domain controller that belongs to a particular site. 2ff7e9595c
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