Active Directory includes functionality called Sites and Subnets that associates domain controllers with one or more locations and defines proximity
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See Active Directory Networks for information about the network subnets containing Active Directory components such as domain controllers |
Overview
The Sites and Subnets of an Active Directory define the association between domain controllers and domainwell-joined clientsconnected locations. Each Site is a named collection of a one or more domain controllers and as well as one or more subnets. Domain-joined clients locate the closest domain controller by querying Windows devices connected to Active Directory will, by default, leverage the Site configuration to locate the nearest domain controller by performing the following steps:
Query Active Directory for the sites and subnets
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information
Identify the site that has a subnet value which best matches the IP address on the client
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Select a domain controller from the site identified in the previous step
The site selection behavior can be overridden via Group Policy. The "Specify site name" policy at "Computer Configuration\Administrative Tempates\System\Net Logon" can be enabled and configured with the Site Name from the table below to force a device to use a specific site.
Site Codes
The Austin Active Directory defines three-character site codes to provide an abbreviated reference to a site. The site codes are split into two general groups: campus site codes for sites associated with networks on campus and cloud site codes for sites associated with networks hosted by cloud providers. Campus site codes are simple abbreviations (aus, atx, pub, etc.) while cloud site codes follow a general rule:
the first character is
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an abbreviation for the cloud provider
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: sites in AWS start with 'w'
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and sites in Azure start with 'z'
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the second and third characters are abbreviations for specific regions in the cloud provider .
Site Details
The Austin Active Directory defines multiple sites and subnets to associate domain controllers with specific physical locations both on-campus and in the cloud.
Sites in the Austin Active Directory
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Site Name | Site Code | Domain Controllers | Subnets | Notes |
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Austin-Public | pub | Public DCs | Public DC subnets |
Sites in the Austin Active Directory - Future
provide DNS resolution and AD services to specific off-campus customers | ||
Austin-Services | atx | Service DCs |
for applications | Service DC subnets, RODC subnets |
load-balanced DCs on campus |
AWS-US-East-1 | we1 | Cloud DCs in AWS US East 1 region | Subnets in AWS US East 1 region | |
Azure-South-Central | zsc | Cloud DCs in Azure South Central region | Subnets in Azure South Central region | |
Azure-West-US-2 | zw2 | Cloud DCs in Azure West US 2 region | Subnets in Azure West US 2 region | |
Default-First-Site-Name |
aus |
Campus DCs |
On-campus subnets |
not in other sites | will align Active Directory site code with CM site code |