Tag: Replication

Systems Admin

Universal Group Membership Caching

How to enable Universal Group Membership Caching (UGMC) on a remote AD site so user logons no longer have to traverse a slow WAN to a Global Catalog. Walks the GUI three-click path (Sites and Services > site > NTDS Site Settings > Properties > Enable UGMC) with the actual screenshots, the Set-ADObject PowerShell equivalent (one bit on the NTDS Site Settings options attribute, 0x20), the design choice between UGMC and a local Global Catalog, the 8-hour cache refresh behaviour, and the common pitfalls (right-clicking the wrong node, first-logon needs the GC, stale cache after Universal Group changes).

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Systems Admin

Configure a Domain Controller as a Global Catalog Server

How to add the Global Catalog flag to an existing Domain Controller in Active Directory Sites and Services, and the PowerShell equivalent (one bit on the NTDS Settings options attribute via Set-ADObject). Walks the GUI three-click path, the Set-ADObject cmdlet, post-change verification with Get-ADDomainController IsGlobalCatalog / dsquery server -isgc / repadmin /options / Test-NetConnection on port 3268, the partial-attribute-set replication timing caveat, and the common pitfalls (right-clicking the wrong tree node, leaving only one GC, demoting accidentally).

10 min read
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Systems Admin

Active Directory Health Check with PowerShell

One PowerShell script that wraps dcdiag, Test-Connection, Resolve-DnsName, w32tm, Get-Service, and CIM into a single colored HTML report — one row per Domain Controller, 35 columns of pass/warn/fail per cell. Includes the full Get-ADHealth.ps1 source, what each dcdiag test actually catches (Connectivity, SysVolCheck, KccEvent, FSMOCheck, NCSecDesc, etc.), how to schedule a daily SMTP-emailed run, the MotW / Unblock-File / ExecutionPolicy gotchas, and the green-DNS-red-everything-else fingerprint that means a DC is offline.

21 min read
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Systems Admin

Configure and Manage Active Directory Sites and Services

Learn how to configure Active Directory Sites and Services for a multi-site environment. This step-by-step guide covers creating AD sites, configuring site links with costs, setting the replication interval and schedule, mapping IP subnets to sites, and managing site link bridging for efficient domain controller replication.

10 min read
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