(2014-02-01) Testing Active Directory Replication Latency/Convergence Through PowerShell (Update 2)

UPDATE: A newer version of this blog post and the PowerShell script can be found here.

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I have updated the PowerShell script for testing/determining Active Directory Replication Latency/Convergence.

Detailed information about the script can be read here.

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This script requires PowerShell v2.0 or higher

The script supports: W2K3(R2) DCs, W2K8(R2) DC and W2K12(R2) DCs

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The code of the PowerShell script that does this is included below. Screen dumps are also included after the code sample.

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!!! DISCLAIMER/REMARKS !!!:

• The script is freeware, you are free to distribute it, but always refer to this website as the location where you got it
• This script is furnished "as is". No warranty is expressed or implied!
• Always test first in lab environment to see if it meets your needs!
• Use this script at your own risk!
• I do not warrant this script to be fit for any purpose, use or environment
• I have tried to check everything that needed to be checked, but I do not guarantee the script does not have bugs.
• I do not guarantee the script will not damage or destroy your system(s), environment or whatever.
• I do not accept liability in any way if you screw up, use the script wrong or in any other way where damage is caused to your environment/systems!
• If you do not accept these terms do not use the script and delete it immediately!

!!! DISCLAIMER/REMARKS !!!:

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I have also linked a file with the contents below to this blog post. Get the most up-to-date version HERE.

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# Abstract: This PoSH Script Checks The AD Replication Latency/Convergence
# Re-Written by: Jorge de Almeida Pinto [MVP-DS]
# Blog: https://jorgequestforknowledge.wordpress.com/
#
# 2013-03-02: (v0.1): Initial version of the script (v0.1)
# 2014-02-01: (v0.2): Added STOP option, added few extra columns to output extra info of DCs, better detection of unavailable DCs/GCs, and screen adjustment section added (v0.2)
#

# Clear The Screen
Clear-Host

# Configure The Appropriate Screen And Buffer Size To Make Sure Everything Fits Nicely
$uiConfig = (Get-Host).UI.RawUI
$uiConfig.WindowTitle = "+++ CHECKING AD REPLICATION LATENCY +++"
$uiConfig.ForegroundColor = "Yellow"
$uiConfigBufferSize = $uiConfig.BufferSize
$uiConfigBufferSize.Width = 120
$uiConfigBufferSize.Height = 9999
$uiConfigScreenSizeMax = $uiConfig.MaxPhysicalWindowSize
$uiConfigScreenSizeMaxWidth = $uiConfigScreenSizeMax.Width
$uiConfigScreenSizeMaxHeight = $uiConfigScreenSizeMax.Height
$uiConfigScreenSize = $uiConfig.WindowSize
If ($uiConfigScreenSizeMaxWidth -lt 120) {
    $uiConfigScreenSize.Width = $uiConfigScreenSizeMaxWidth
} Else {
    $uiConfigScreenSize.Width = 120
}
If ($uiConfigScreenSizeMaxHeight -lt 75) {
    $uiConfigScreenSize.Height = $uiConfigScreenSizeMaxHeight - 5
} Else {
    $uiConfigScreenSize.Height = 75
}
$uiConfig.BufferSize = $uiConfigBufferSize
$uiConfig.WindowSize = $uiConfigScreenSize

# Start...
Clear-Host
Write-Host "                                *******************************************************" -ForeGroundColor Magenta
Write-Host "                                *                                                     *" -ForeGroundColor Magenta
Write-Host "                                *   --> Test AD Replication Latency/Convergence <--   *" -ForeGroundColor Magenta
Write-Host "                                *                                                     *" -ForeGroundColor Magenta
Write-Host "                                *    Re-Written By: Jorge de Almeida Pinto [MVP-DS]   *" -ForeGroundColor Magenta
Write-Host "                                *    (https://jorgequestforknowledge.wordpress.com/)   *" -ForeGroundColor Magenta
Write-Host "                                *                                                     *" -ForeGroundColor Magenta
Write-Host "                                *******************************************************" -ForeGroundColor Magenta

##########
# Some Constants
$continue = $true
$cleanupTempObject = $true

##########
# The Function To Test The Port Connection
Function PortConnectionCheck($fqdnDC,$port,$timeOut) {
    $tcpPortSocket = $null
    $portConnect = $null
    $tcpPortWait = $null
    $tcpPortSocket = New-Object System.Net.Sockets.TcpClient
    $portConnect = $tcpPortSocket.BeginConnect($fqdnDC,$port,$null,$null)
    $tcpPortWait = $portConnect.AsyncWaitHandle.WaitOne($timeOut,$false)
    If(!$tcpPortWait) {
        $tcpPortSocket.Close()
        #Write-Host "Connection Timeout"
        Return "ERROR"
    } Else {
        #$error.Clear()
        $ErrorActionPreference = "SilentlyContinue"
        $tcpPortSocket.EndConnect($portConnect) | Out-Null
        If (!$?) {
            #Write-Host $error[0]
            Return "ERROR"
        } Else {
            Return "SUCCESS"
        }
        $tcpPortSocket.Close()
        $ErrorActionPreference = "Continue"
    }
}

##########
# Get List Of AD Domains In The AD Forest, Create And Present In A Table
$ThisADForest = [DirectoryServices.ActiveDirectory.Forest]::GetCurrentForest()
$ListOfADDomainsInADForest = $ThisADForest.Domains
$TableOfADDomainsInADForest = @()
Write-Host ""
Write-Host "---------------------------------------------------------------------------------------------------------------------" -ForeGroundColor Cyan
Write-Host "LIST OF DOMAINs IN THE AD FOREST..." -ForeGroundColor Cyan
Write-Host ""
Write-Host "Forest Mode/Level...: "$ThisADForest.ForestMode
ForEach ($Domain in $ListOfADDomainsInADForest) {
    $TableOfADDomainsInADForestObj = "" | Select Name,RootDomain,DomainMode,CurrentDomain
    $TableOfADDomainsInADForestObj.Name = $Domain.Name
    $TableOfADDomainsInADForestObj.RootDomain = "FALSE"
    If ($ThisADForest.RootDomain -like $Domain.Name) {
        $TableOfADDomainsInADForestObj.RootDomain = "TRUE"
    }
    $TableOfADDomainsInADForestObj.DomainMode = $Domain.DomainMode

    If ($Domain.Name -like $ENV:USERDNSDOMAIN) {
        $TableOfADDomainsInADForestObj.CurrentDomain = "TRUE"
    } Else {
        $TableOfADDomainsInADForestObj.CurrentDomain = "FALSE"
    }
    $TableOfADDomainsInADForest += $TableOfADDomainsInADForestObj
}
$TableOfADDomainsInADForest | FT -AutoSize
Write-Host "  --> Found [$($ListOfADDomainsInADForest.count)] AD Domain(s) In AD Forest..." -ForeGroundColor Cyan
Write-Host ""

##########
# Get List Of GCs In AD Forest, Create And Present In A Table
$ListOfGCsInADForest = $ThisADForest.GlobalCatalogs
$TableOfGCsInADForest = @()
Write-Host "---------------------------------------------------------------------------------------------------------------------" -ForeGroundColor Cyan
Write-Host "LIST OF GCs IN THE AD FOREST '$ThisADForest'..." -ForeGroundColor Cyan
ForEach ($GC in $ListOfGCsInADForest) {
    $TableOfGCsInADForestObj = "" | Select Name,Domain,"Site Name","IP Address","OS Version"
    $TableOfGCsInADForestObj.Name = $GC.Name
    If ($GC.Domain -ne $null -And $GC.Domain -ne "") {
        $TableOfGCsInADForestObj.Domain = $GC.Domain
    } Else {
        $TableOfGCsInADForestObj.Domain = "<Fail>"
    }
    If ($GC.SiteName -ne $null -And $GC.SiteName -ne "") {
        $TableOfGCsInADForestObj."Site Name" = $GC.SiteName
    } Else {
        $TableOfGCsInADForestObj."Site Name" = "<Fail>"
    }
    If ($GC.IPAddress -ne $null -And $GC.IPAddress -ne "") {
        $TableOfGCsInADForestObj."IP Address" = $GC.IPAddress
    } Else {
        $TableOfGCsInADForestObj."IP Address" = "<Fail>"
    }
    If ($GC.OSVersion -ne $null -And $GC.OSVersion -ne "") {
        $TableOfGCsInADForestObj."OS Version" = $GC.OSVersion
    } Else {
        $TableOfGCsInADForestObj."OS Version" = "<Fail>"
    }
    $TableOfGCsInADForest += $TableOfGCsInADForestObj
}
$TableOfGCsInADForest | FT -AutoSize
Write-Host "  --> Found [$($ListOfGCsInADForest.count)] GC(s) In AD Forest..." -ForeGroundColor Cyan
Write-Host ""

##########
# Determine Which AD Domain To Use For The Temp Object. This Does Assume The Correct Permissions In That AD Domain To Create/Delete The Object!
Write-Host "---------------------------------------------------------------------------------------------------------------------" -ForeGroundColor Cyan
Write-Host "In Which AD Domain Should The Temp Object Be Created?" -ForeGroundColor Cyan
Write-Host ""
$ADDomainToWriteTo = Read-Host "Please Provide FQDN Or Just Press ENTER For Current AD Domain"

# If No FQDN Of An AD Domain Is Specified, Then Use The Local AD Domain
If ($ADDomainToWriteTo -eq "") {
    $ADDomainToWriteTo = $(Get-WmiObject -Class Win32_ComputerSystem).Domain
}

# If The FQDN Of An AD Domain Is Specified, Then Check If It Exists In This AD Forest
If ($ADDomainToWriteTo -ne "") {
    $ADdomainvalidity = $False
    ForEach ($Domain in $ListOfADDomainsInADForest) {
        If ($Domain.Name -like $ADDomainToWriteTo) {
            $ADdomainvalidity = $True
        }
    }
    Write-Host ""
    Write-Host "Checking Existence Of The Specified AD Domain '$ADDomainToWriteTo' In The AD Forest..." -ForeGroundColor Yellow
    If ($ADdomainvalidity -eq $True) {
        Write-Host ""
        Write-Host "The Specified AD Domain '$ADDomainToWriteTo' Exists In The AD Forest!" -ForeGroundColor Green
        Write-Host ""
        Write-Host "Continuing Script..." -ForeGroundColor Green
    }
    If ($ADdomainvalidity -eq $False) {
        Write-Host ""
        Write-Host "The Specified AD Domain '$ADDomainToWriteTo' Does Not Exist In The AD Forest!" -ForeGroundColor Red
        Write-Host ""
        Write-Host "Please Re-Run The Script And Provide The FQDN Of An AD Domain That Does Exist In The AD Forest" -ForeGroundColor Red
        Write-Host ""
        Write-Host "Aborting Script..." -ForeGroundColor Red
        Write-Host ""
        BREAK
    }
}
Write-Host ""

##########
# Get List Of DCs In AD Domain, Create And Present In A Table
$contextADDomainToWriteTo = New-Object System.DirectoryServices.ActiveDirectory.DirectoryContext("Domain",$ADDomainToWriteTo)
$ListOfDCsInADDomain = [System.DirectoryServices.ActiveDirectory.DomainController]::findall($contextADDomainToWriteTo)
$TableOfDCsInADDomain = @()
Write-Host "---------------------------------------------------------------------------------------------------------------------" -ForeGroundColor Cyan
Write-Host "LIST OF DCs IN THE AD DOMAIN '$ADDomainToWriteTo'..." -ForeGroundColor Cyan
ForEach ($DC in $ListOfDCsInADDomain) {
    $TableOfDCsInADDomainObj = "" | Select Name,Domain,GC,FSMO,"Site Name","DS type","IP Address","OS Version"
    $TableOfDCsInADDomainObj.Name = $DC.Name
    $TableOfDCsInADDomainObj.Domain = $ADDomainToWriteTo
    $TableOfDCsInADDomainObj.GC = "FALSE"
    ForEach ($GC in $ListOfGCsInADForest) {
        If ($DC.Name -like $GC.Name) {
            $TableOfDCsInADDomainObj.GC = "TRUE"
        }
    }
    If ($DC.Roles -ne $null) {
        If ($DC.Roles -Contains "PdcRole") {
            $pdcFQDN = $DC.Name
            $pdcDomain = $ADDomainToWriteTo
            $pdcSite = $DC.SiteName
        }
        ForEach ($FSMO In $DC.Roles) {
            If ($FSMO -eq "SchemaRole") {$FSMO = "SCH"}
            If ($FSMO -eq "NamingRole") {$FSMO = "DNM"}
            If ($FSMO -eq "PdcRole") {$FSMO = "PDC"}
            If ($FSMO -eq "RidRole") {$FSMO = "RID"}
            If ($FSMO -eq "InfrastructureRole") {$FSMO = "INF"}
            $TableOfDCsInADDomainObj.FSMO += $FSMO+"/"
        }
        $TableOfDCsInADDomainObj.FSMO = ($TableOfDCsInADDomainObj.FSMO).SubString(0,$TableOfDCsInADDomainObj.FSMO.Length-1)
    } Else {
        $TableOfDCsInADDomainObj.FSMO = "....."
    }
    If ($DC.SiteName -ne $null -And $DC.SiteName -ne "") {
        $TableOfDCsInADDomainObj."Site Name" = $DC.SiteName
    } Else {
        $TableOfDCsInADDomainObj."Site Name" = "<Fail>"
    }
    
    $ListOfRWDCsInADDomain = [System.DirectoryServices.ActiveDirectory.DomainController]::findall($contextADDomainToWriteTo) | ?{$_.OutboundConnections -ne $null}
    $DStype = "Read-Only"
    ForEach ($RWDC In $ListOfRWDCsInADDomain) {
        If ($RWDC.Name -like $DC.Name) {
            $DStype = "Read/Write"
            Break
        }
    }
    $TableOfDCsInADDomainObj."DS Type" = $DStype
    If ($DC.IPAddress -ne $null -And $DC.IPAddress -ne "") {
        $TableOfDCsInADDomainObj."IP Address" = $DC.IPAddress
    } Else {
        $TableOfDCsInADDomainObj."IP Address" = "<Fail>"
    }
    If ($DC.OSVersion -ne $null -And $DC.OSVersion -ne "") {
        $TableOfDCsInADDomainObj."OS Version" = $DC.OSVersion
    } Else {
        $TableOfDCsInADDomainObj."OS Version" = "<Fail>"
    }
    $TableOfDCsInADDomain += $TableOfDCsInADDomainObj
}
$TableOfDCsInADDomain | FT -AutoSize
Write-Host "  --> Found [$($ListOfDCsInADDomain.count)] DC(s) In AD Domain..." -ForeGroundColor Cyan
Write-Host ""

##########
# Specify A RWDC From The Selected AD Domain
Write-Host "---------------------------------------------------------------------------------------------------------------------" -ForeGroundColor Cyan
Write-Host "Which RWDC In The AD Domain '$ADDomainToWriteTo' Should Be Used To Create The Object?" -ForeGroundColor Cyan
Write-Host ""
Write-Host "Available Options Are:" -ForeGroundColor Yellow
Write-Host "[*] Specify 'PDC' To Use The DC With The PDC FSMO Role" -ForeGroundColor Yellow
Write-Host "[*] Just Press Enter To Locate An RWDC" -ForeGroundColor Yellow
Write-Host "[*] Specify The FQDN Of A Specific RWDC" -ForeGroundColor Yellow
Write-Host "[*] Specify 'STOP' To End The Script" -ForeGroundColor Yellow
Write-Host ""
$SourceRWDCInADDomain = Read-Host "Please Choose An Option"

# If PDC Was Specified Find The RWDC With The PDC FSMO Role And Use That
If ($SourceRWDCInADDomain -eq "PDC") {
    $SourceRWDCInADDomainFQDN = $pdcFQDN
    $SourceRWDCInADDomainDOMAIN = $pdcDomain
    $SourceRWDCInADDomainSITE = $pdcSite
}

# If Nothing Was Specified Automatically Locate An RWDC To Use
If ($SourceRWDCInADDomain -eq "") {
    # Locate Just ONE DC (This Could Be An RWDC Or RODC)
    $SourceRWDCInADDomainObjectONE = [System.DirectoryServices.ActiveDirectory.DomainController]::findone($contextADDomainToWriteTo)
    
    # Locate All RWDCs In The AD Domain
    $SourceRWDCInADDomainObjectALL = [System.DirectoryServices.ActiveDirectory.DomainController]::findall($contextADDomainToWriteTo) | ?{$_.OutboundConnections -ne $null}
    $UseRWDC = $False

    # Check If The Single DC Found Is An RWDC Or Not By Checking If It Is In The List Of RWDCs
    ForEach ($RWDC In $SourceRWDCInADDomainObjectALL) {
        If ($RWDC.Name -like $SourceRWDCInADDomainObjectONE.Name) {
            $UseRWDC = $True
        }
    }
    
    # If The Single DC Found Is An RWDC, Then Use That One
    If ($UseRWDC -eq $True) {
        $SourceRWDCInADDomainFQDN = $SourceRWDCInADDomainObjectONE.Name
        $SourceRWDCInADDomainDOMAIN = $SourceRWDCInADDomainObjectONE.Domain
        $SourceRWDCInADDomainSITE = $SourceRWDCInADDomainObjectONE.SiteName
    }
    
    # If The Single DC Found Is An RODC, Then Find The RWDC With The PDC FSMO Role And Use That
    If ($UseRWDC -eq $False) {
        $SourceRWDCInADDomainFQDN = $pdcFQDN
        $SourceRWDCInADDomainDOMAIN = $pdcDomain
        $SourceRWDCInADDomainSITE = $pdcSite
    }
}

# If A Specific RWDC Was Specified Then Use That One
If ($SourceRWDCInADDomain -ne "" -And $SourceRWDCInADDomain -ne "PDC" -And $SourceRWDCInADDomain -ne "STOP") {
    $contextRWDCToWriteTo = New-Object System.DirectoryServices.ActiveDirectory.DirectoryContext("DirectoryServer",$SourceRWDCInADDomain)
    $SourceRWDCInADDomainObject = [System.DirectoryServices.ActiveDirectory.DomainController]::GetDomainController($contextRWDCToWriteTo)
    $SourceRWDCInADDomainFQDN = $SourceRWDCInADDomainObject.Name
    $SourceRWDCInADDomainDOMAIN = $SourceRWDCInADDomainObject.Domain
    $SourceRWDCInADDomainSITE = $SourceRWDCInADDomainObject.SiteName    
}

# If STOP Was Specified Then End The Script
If ($SourceRWDCInADDomain -eq "STOP") {
    Write-Host ""
    Write-Host "'STOP' Was Specified..." -ForeGroundColor Red
    Write-Host "Aborting Script..." -ForeGroundColor Red
    Write-Host ""
    EXIT    
}

# Check If The Selected DC Actually Exists In The AD Domain And Its Is An RWDC And NOT An RODC
$RWDCvalidity = $False
ForEach ($DC in $ListOfRWDCsInADDomain) {
    If ($DC.Name -like $SourceRWDCInADDomainFQDN) {
        $RWDCvalidity = $True
    }
}
Write-Host ""
Write-Host "Checking Existence And Connectivity Of The Specified RWDC '$SourceRWDCInADDomainFQDN' In The AD Domain '$ADDomainToWriteTo'..." -ForeGroundColor Yellow
If ($RWDCvalidity -eq $True) {
    Write-Host ""
    Write-Host "The Specified DC '$SourceRWDCInADDomainFQDN' Is An RWDC And It Exists In The AD Domain '$ADDomainToWriteTo'!" -ForeGroundColor Green
    Write-Host ""
    Write-Host "Continuing Script..." -ForeGroundColor Green
    $ldapPort = "389"
    $timeOut = "500"
    $ldapConnectionResult = $null
    $fqdnDC = $SourceRWDCInADDomainFQDN
    $ldapConnectionResult = PortConnectionCheck $fqdnDC $ldapPort $timeOut
    If ($ldapConnectionResult -eq "SUCCESS") {
        Write-Host ""
        Write-Host "The Specified RWDC '$SourceRWDCInADDomainFQDN' Is Reachable!" -ForeGroundColor Green
        Write-Host ""
        Write-Host "Continuing Script..." -ForeGroundColor Green
        Write-Host ""
    }
    If ($ldapConnectionResult -eq "ERROR") {
        Write-Host ""
        Write-Host "The Specified RWDC '$SourceRWDCInADDomainFQDN' Is NOT Reachable!" -ForeGroundColor Red
        Write-Host ""
        Write-Host "Please Re-Run The Script And Make Sure To Use An RWDC That Is Reachable!" -ForeGroundColor Red
        Write-Host ""
        Write-Host "Aborting Script..." -ForeGroundColor Red
        Write-Host ""
        Break
    }
}
If ($RWDCvalidity -eq $False) {
    Write-Host ""
    Write-Host "The Specified DC '$SourceRWDCInADDomainFQDN' Either Does NOT Exist In The AD Domain '$ADDomainToWriteTo' Or Is NOT And RWDC!" -ForeGroundColor Red
    Write-Host ""
    Write-Host "Please Re-Run The Script And Provide The FQDN Of An RWDC Within The AD Domain '$ADDomainToWriteTo' That Does Exist" -ForeGroundColor Red
    Write-Host ""
    Write-Host "Aborting Script..." -ForeGroundColor Red
    Write-Host ""
    Break
}

##########
# Get List Of DCs/GCs In AD Domain/Forest To Which The Temp Object Will Replicate, Create And Present In A Table
Write-Host "---------------------------------------------------------------------------------------------------------------------" -ForeGroundColor Cyan
Write-Host "LIST OF DIRECTORY SERVERS THE TEMP OBJECT REPLICATES TO..." -ForeGroundColor Cyan

# Put The Selected RWDC Already In the Table [A] Of Directory Servers To Which The Temp Object Will Replicate
$TableOfDSServersA = @()
$TableOfDSServersAObj = "" | Select Name,Domain,GC,"Site Name",Reachable
$TableOfDSServersAObj.Name = ("$SourceRWDCInADDomainFQDN [SOURCE RWDC]").ToUpper()
$TableOfDSServersAObj.Domain = $ADDomainToWriteTo
$TableOfDSServersAObj.GC = "FALSE"
ForEach ($GC in $ListOfGCsInADForest) {
    If ($SourceRWDCInADDomainFQDN -like $GC.Name) {
        $TableOfDSServersAObj.GC = "TRUE"
    }
}
$TableOfDSServersAObj."Site Name" = $SourceRWDCInADDomainSITE
$TableOfDSServersAObj.Reachable = "TRUE"
$TableOfDSServersA += $TableOfDSServersAObj

# Put The Selected RWDC Already In the Table [B] Of Directory Servers Where The Replication Starts
$TableOfDSServersB = @()
$TableOfDSServersBObj = "" | Select Name,Domain,GC,"Site Name",Time
$TableOfDSServersBObj.Name = ("$SourceRWDCInADDomainFQDN [SOURCE RWDC]").ToUpper()
$TableOfDSServersBObj.Domain = $ADDomainToWriteTo
$TableOfDSServersBObj.GC = "FALSE"
ForEach ($GC in $ListOfGCsInADForest) {
    If ($SourceRWDCInADDomainFQDN -like $GC.Name) {
        $TableOfDSServersBObj.GC = "TRUE"
    }
}
$TableOfDSServersBObj."Site Name" = $SourceRWDCInADDomainSITE
$TableOfDSServersBObj.Time = 0.00
$TableOfDSServersB += $TableOfDSServersBObj

# Add All Other Remaining DCs In The Targeted AD Domain To The List Of Directory Servers [A]
ForEach ($DC In $ListOfDCsInADDomain) {
    If(!($DC.Name -like $SourceRWDCInADDomainFQDN)) {
        $TableOfDSServersAObj = "" | Select Name,Domain,GC,"Site Name",Reachable
        $TableOfDSServersAObj.Name = $DC.Name
        If ($DC.Domain -ne $null -And $DC.Domain -ne "") {
            $TableOfDSServersAObj.Domain = $DC.Domain
        } Else {
            $TableOfDSServersAObj.Domain = "<Fail>"
        }
        $TableOfDSServersAObj.GC = "FALSE"
        ForEach ($GC in $ListOfGCsInADForest) {
            If ($DC.Name -like $GC.Name) {
                $TableOfDSServersAObj.GC = "TRUE"
            }
        }
        If ($DC.SiteName -ne $null -And $DC.SiteName -ne "") {
            $TableOfDSServersAObj."Site Name" = $DC.SiteName
        } Else {
            $TableOfDSServersAObj."Site Name" = "<Fail>"
        }
        $ldapPort = "389"
        $timeOut = "500"
        $ldapConnectionResult = $null
        $fqdnDC = $DC.Name
        $ldapConnectionResult = PortConnectionCheck $fqdnDC $ldapPort $timeOut
        If ($ldapConnectionResult -eq "SUCCESS") {
            $TableOfDSServersAObj.Reachable = "TRUE"
        }
        If ($ldapConnectionResult -eq "ERROR") {
            $TableOfDSServersAObj.Reachable = "FALSE"
        }
        $TableOfDSServersA += $TableOfDSServersAObj
    }
}

# Add All Other Remaining GCs In The AD Forest To The List Of Directory Servers [A]
ForEach ($GC In $ListOfGCsInADForest) {
    $ToBeAdded = $True
    ForEach ($DC In $ListOfDCsInADDomain) {
        If($DC.Name -like $GC.Name) {
            $ToBeAdded = $False
        }
    }
    If ($ToBeAdded) {
        $TableOfDSServersAObj = "" | Select Name,Domain,GC,"Site Name",Reachable
        $TableOfDSServersAObj.Name = $GC.Name
        If ($GC.Domain -ne $null -And $GC.Domain -ne "") {
            $TableOfDSServersAObj.Domain = $GC.Domain
        } Else {
            $TableOfDSServersAObj.Domain = "<Fail>"
        }
        $TableOfDSServersAObj.GC = "TRUE"
        If ($GC.SiteName -ne $null -And $GC.SiteName -ne "") {
            $TableOfDSServersAObj."Site Name" = $GC.SiteName
        } Else {
            $TableOfDSServersAObj."Site Name" = "<Fail>"
        }
        $gcPort = "3268"
        $timeOut = "500"
        $gcConnectionResult = $null
        $fqdnGC = $GC.Name
        $gcConnectionResult = PortConnectionCheck $fqdnGC $gcPort $timeOut
        If ($gcConnectionResult -eq "SUCCESS") {
            $TableOfDSServersAObj.Reachable = "TRUE"
        }
        If ($gcConnectionResult -eq "ERROR") {
            $TableOfDSServersAObj.Reachable = "FALSE"
        }
        $TableOfDSServersA += $TableOfDSServersAObj
    }
}
$TableOfDSServersA | FT -AutoSize
Write-Host "  --> Found [$($TableOfDSServersA.count)] Directory Server(s)..." -ForeGroundColor Cyan
Write-Host ""

##########
# Create The Temp Object On The Targeted RWDC
Write-Host "---------------------------------------------------------------------------------------------------------------------" -ForeGroundColor Cyan
Write-Host "CREATING TEMP CONTACT OBJECT IN AD...:" -ForeGroundColor Cyan
Write-Host ""
$domainNCDN = (([ADSI]"LDAP://$SourceRWDCInADDomainFQDN/rootDSE").defaultNamingContext)
$container = "CN=Users," + $domainNCDN
$tempObjectName = "adReplTempObject" + (Get-Date -f yyyyMMddHHmmss)
Write-Host "  --> On RWDC.............: $SourceRWDCInADDomainFQDN" -ForeGroundColor Yellow
Write-Host "  --> With Full Name......: $tempObjectName" -ForeGroundColor Yellow
Write-Host "  --> With Description....: ...!!!...TEMP OBJECT TO TEST AD REPLICATION LATENCY/CONVERGENCE...!!!..." -ForeGroundColor Yellow
Write-Host "  --> In AD Domain........: $ADDomainToWriteTo ($domainNCDN)" -ForeGroundColor Yellow
Write-Host "  --> In Container........: $container" -ForeGroundColor Yellow
$tempObject = ([ADSI]"LDAP://$SourceRWDCInADDomainFQDN/$container").Create("contact","CN=$tempObjectName")
$tempObject.Put("Description","...!!!...TEMP OBJECT TO TEST AD REPLICATION LATENCY/CONVERGENCE...!!!...")
$tempObject.SetInfo()
$tempObjectDN = $tempObject.distinguishedname
Write-Host "`n  Temp Contact Object [$tempObjectDN] Has Been Created On RWDC [$SourceRWDCInADDomainFQDN]! `n" -ForeGroundColor Yellow

##########
# Go Through The Process Of Checking Each Directory Server To See If The Temp Object Already Has Replicated To It
$startDateTime = Get-Date
$i = 0
Write-Host "  --> Found [$($TableOfDSServersA.count)] Directory Server(s)..." -ForeGroundColor Yellow
Write-Host ""
While($continue) {
    $i++
    $oldpos = $host.UI.RawUI.CursorPosition
    Write-Host "  ====================== CHECK $i ======================" -ForeGroundColor Yellow
    Write-Host ""
    Write-Host "  REMARK: Each DC In The List Below Must Be Accessible Through LDAP Over TCP (389)" -ForeGroundColor Red
    Write-Host "  REMARK: Each GC In The List Below Must Be Accessible Through LDAP-GC Over TCP (3268)" -ForeGroundColor Red
    Write-Host ""
    Start-Sleep 1
    $replicated = $true
    
    # For Each Directory Server In The List/Table [A] Perform A Number Of Steps
    ForEach ($DSsrv in $TableOfDSServersA) {
        If ($DSsrv.Name -match $SourceRWDCInADDomainFQDN) {
            Write-Host "  * Contacting DC In AD domain ...[$($DSsrv.Name.ToUpper())]..." -ForeGroundColor Yellow
            Write-Host "     - DC Is Reachable..." -ForeGroundColor Green
            Write-Host "     - Object [$tempObjectDN] Exists In The Database" (" "*3) -ForeGroundColor Green
            continue
        }

        # If The Directory Server Is A DC In The AD Domain, Then Connect Through LDAP (TCP:389)
        If ($DSsrv.Domain -like $ADDomainToWriteTo) {
            Write-Host ""
            Write-Host "  * Contacting DC In AD domain ...[$($DSsrv.Name.ToUpper())]..." -ForeGroundColor Yellow
            $connectionResult = $null
            If ($DSsrv.Reachable -eq "TRUE") {
                Write-Host "     - DC Is Reachable..." -ForeGroundColor Green
                $objectPath = [ADSI]"LDAP://$($DSsrv.Name)/$tempObjectDN"
                $connectionResult = "SUCCESS"
            }            
            If ($DSsrv.Reachable -eq "FALSE") {
                Write-Host "     - DC Is NOT Reachable..." -ForeGroundColor Red
                $connectionResult = "FAILURE"
            }            
        }
        
        # If The Directory Server Is A GC In Another AD Domain, Then Connect Through LDAP-GC (TCP:3268)
        If (!($DSsrv.Domain -like $ADDomainToWriteTo) -And $DSsrv.Domain -ne $null -And $DSsrv.Domain -ne "" -And $DSsrv.Domain -ne "<Fail>") {
            Write-Host ""
            Write-Host "  * Contacting GC In Other AD Domain ...[$($DSsrv.Name.ToUpper())]..." -ForeGroundColor Yellow
            $connectionResult = $null
            If ($DSsrv.Reachable -eq "TRUE") {
                Write-Host "     - DC Is Reachable..." -ForeGroundColor Green
                $objectPath = [ADSI]"GC://$($DSsrv.Name)/$tempObjectDN"
                $connectionResult = "SUCCESS"
            }            
            If ($DSsrv.Reachable -eq "FALSE") {
                Write-Host "     - DC Is NOT Reachable..." -ForeGroundColor Red
                $connectionResult = "FAILURE"
            }
        }
        # If The Directory Server Is Not Available
        If ($DSsrv.Domain -eq $null -Or $DSsrv.Domain -eq "" -Or $DSsrv.Domain -eq "<Fail>") {
            Write-Host ""
            Write-Host "  * Contacting DC/GC In AD Forest ...[$($DSsrv.Name.ToUpper())]..." -ForeGroundColor Yellow
            $connectionResult = $null        
            If ($DSsrv.Reachable -eq "FALSE") {
                Write-Host "     - DC Is NOT Reachable..." -ForeGroundColor Red
                $connectionResult = "FAILURE"
            }
        }
        
        # If The Connection To The DC Is Successful
        If ($connectionResult -eq "SUCCESS") {
            If ($objectPath.name) {
                # If The Temp Object Already Exists
                Write-Host "     - Object [$tempObjectDN] Now Does Exist In The Database" (" "*3) -ForeGroundColor Green
                If (!($TableOfDSServersB | ?{$_.Name -match $DSsrv.Name})) {
                    $TableOfDSServersBobj = "" | Select Name,Domain,GC,"Site Name",Time
                    $TableOfDSServersBobj.Name = $DSsrv.Name
                    $TableOfDSServersBObj.Domain = $DSsrv.Domain
                    $TableOfDSServersBObj.GC = $DSsrv.GC
                    $TableOfDSServersBObj."Site Name" = $DSsrv."Site Name"
                    $TableOfDSServersBObj.Time = ("{0:n2}" -f ((Get-Date)-$startDateTime).TotalSeconds)
                    $TableOfDSServersB += $TableOfDSServersBObj
                }
            } Else {
                # If The Temp Object Does Not Yet Exist
                Write-Host "     - Object [$tempObjectDN] Does NOT Exist Yet In The Database" -ForeGroundColor Red
                $replicated  = $false
            }
        }
        
        # If The Connection To The DC Is Unsuccessful
        If ($connectionResult -eq "FAILURE") {
            Write-Host "     - Unable To Connect To DC/GC And Check For The Temp Object..." -ForeGroundColor Red
            If (!($TableOfDSServersB | ?{$_.Name -match $DSsrv.Name})) {
                $TableOfDSServersBobj = "" | Select Name,Domain,GC,"Site Name",Time
                $TableOfDSServersBobj.Name = $DSsrv.Name
                $TableOfDSServersBObj.Domain = $DSsrv.Domain
                $TableOfDSServersBObj.GC = $DSsrv.GC
                $TableOfDSServersBObj."Site Name" = $DSsrv."Site Name"
                $TableOfDSServersBObj.Time = "<Fail>"
                $TableOfDSServersB += $TableOfDSServersBObj
            }
        }
    }
    If ($replicated) {
        $continue = $false
    } Else {
        $host.UI.RawUI.CursorPosition = $oldpos
    }
}

##########
# Show The Start Time, The End Time And The Duration Of The Replication
$endDateTime = Get-Date
$duration = "{0:n2}" -f ($endDateTime.Subtract($startDateTime).TotalSeconds)
Write-Host "`n  Start Time......: $(Get-Date $startDateTime -format "yyyy-MM-dd HH:mm:ss")" -ForeGroundColor Yellow
Write-Host "  End Time........: $(Get-Date $endDateTime -format "yyyy-MM-dd HH:mm:ss")" -ForeGroundColor Yellow
Write-Host "  Duration........: $duration Seconds" -ForeGroundColor Yellow

##########
# Delete The Temp Object On The RWDC
If ($cleanupTempObject) {
    Write-Host ""
    Write-Host "  Deleting Temp Contact Object... `n" -ForeGroundColor Yellow
    ([ADSI]"LDAP://$SourceRWDCInADDomainFQDN/$container").Delete("contact","CN=$tempObjectName")
    Write-Host "  Temp Contact Object [$tempObjectDN] Has Been Deleted On The Target RWDC! `n" -ForeGroundColor Yellow
}

##########
# Output The Table [B] Containing The Information Of Each Directory Server And How Long It Took To Reach That Directory Server After The Creation On The Source RWDC
$TableOfDSServersB | Sort-Object Time | FT -AutoSize

–

SINGLE AD DOMAIN AD FOREST WHERE ALL DCs ARE REACHABLE:

In this case ALL directory servers, except for one RODC, are reachable without any problems! That RODC basically only exists as a pre-created RODC account

I just pressed ENTER to use the current AD domain.

Figure 1: Using The Current AD Domain As The Target AD Domain

–

I chose for the script to find an RWDC as the target RWDC to write the temp object to.

Figure 2: Using The RWDC That Hosts The PDC FSMO Role As The Target RWDC To Write The Temp Object To

–

The temporary object has been created and the script is now checking it on all directory servers (DCs in AD domain and GCs in other AD domains in AD forest if any)

If a DC is marked green, then the temporary AD object has replicated to it and the script found the temporary AD object.

If a DC is marked red, then the temporary AD object has not yet replicated to it OR the DC/GC has been marked as unreachable.

Figure 3: Creating The Temp Object In AD And Enumerating Through Each Directory Server To Determine The Existence Of The Temp Object

–

Figure 4: Still Enumerating Through Each Directory Server To Determine The Existence Of The Temp Object

–

When finished it shows the start time, the end time and the duration of time before the temporary AD object reached all directory servers. It also removed the temporary AD object again to keep stuff clean.

This is a W2K12R2 AD forest/domain that has change notification enabled on all AD site links. So after a change has occurred on a certain RWDC it will notify the very first replication partner after 15 seconds (=default) and each other replication partner with pauses of 3 seconds (=default).

SO looking at the example above the following happened:

• RWDC ‘R2FSRWDC1.ADDMZ.LAN’ is where the creation of the temporary AD object originated;
• After about 15 seconds, RWDC ‘R2FSRWDC1.ADDMZ.LAN’ notified RWDC ‘R2FSRWDC2.ADDMZ.LAN’ and RWDC ‘R2FSRWDC2.ADDMZ.LAN’ inbound replicated the temporary AD object from RWDC ‘R2FSRWDC1.ADDMZ.LAN’;
• About 3 seconds later, RWDC ‘R2FSRWDC1.ADDMZ.LAN’ notified RODC ‘R2FSRODC5.ADDMZ.LAN’ and RODC “R2FSRWDC1.ADDMZ.LAN’ inbound replicated the temporary AD object from RWDC ‘R2FSRWDC1.ADDMZ.LAN’;
• Again 3 seconds later, RWDC ‘R2FSRWDC1.ADDMZ.LAN’ notified RODC ‘R2FSRODC6.ADDMZ.LAN’ and RODC ‘R2FSRODC6.ADDMZ.LAN’ inbound replicated the temporary AD object from RWDC ‘R1FSRWDC1.ADDMZ.LAN’;

Figure 5: The End Result Of The AD Replication Latency/Convergence Test

–

MULTIPLE AD DOMAIN AD FOREST WHERE ALL DCs ARE REACHABLE:

In this case ALL directory servers are reachable without any problems!

I just pressed ENTER to use the current AD domain.

Figure 6: Using The Current AD Domain As The Target AD Domain

–

I chose for the script to use the PDC as the target RWDC to write the temp object to.

Figure 7: Using The RWDC That Hosts The PDC FSMO Role As The Target RWDC To Write The Temp Object To

–

The temporary object has been created and the script is now checking it on all directory servers (DCs in AD domain and GCs in other AD domains in AD forest if any)

If a DC is marked green, then the temporary AD object has replicated to it and the script found the temporary AD object.

If a DC is marked red, then the temporary AD object has not yet replicated to it OR the DC/GC has been marked as unreachable.

Figure 8: Creating The Temp Object In AD And Enumerating Through Each Directory Server To Determine The Existence Of The Temp Object

–

Figure 9: Still Enumerating Through Each Directory Server To Determine The Existence Of The Temp Object

–

When finished it shows the start time, the end time and the duration of time before the temporary AD object reached all directory servers. It also removed the temporary AD object again to keep stuff clean.

This is a W2K12R2 AD forest/domain that has change notification enabled on all AD site links. So after a change has occurred on a certain RWDC it will notify the very first replication partner after 15 seconds (=default) and each other replication partner with pauses of 3 seconds (=default).

SO looking at the example above the following happened:

• RWDC ‘R1FSRWDC1.ADCORP.LAB’ is where the creation of the temporary AD object originated;
• After about 15 seconds, RWDC ‘R1FSRWDC1.ADCORP.LAB’ notified RWDC ‘R1FSRWDC2.ADCORP.LAB’ and RWDC ‘R1FSRWDC2.ADCORP.LAB’ inbound replicated the temporary AD object from RWDC ‘R1FSRWDC1.ADCORP.LAB’;
• About 3 seconds later, RWDC ‘R1FSRWDC1.ADCORP.LAB’ notified RWDC ‘C1FSRWDC1.CHILD.ADCORP.LAB’ and RWDC “C1FSRWDC1.CHILD.ADCORP.LAB’ inbound replicated the temporary AD object from RWDC ‘R1FSRWDC1.ADCORP.LAB’;
• After about 15 seconds of RWDC ‘C1FSRWDC1.CHILD.ADCORP.LAB’ receiving the object, it notified RWDC ‘C1FSRWDC2.CHILD.ADCORP.LAB’ and RWDC ‘C1FSRWDC2.CHILD.ADCORP.LAB’ inbound replicated the temporary AD object from RWDC ‘C1FSRWDC1.CHILD.ADCORP.LAB’;

Figure 10: The End Result Of The AD Replication Latency/Convergence Test

–

For more information on AD replication see:

• How Active Directory Replication Topology Works
• How the Active Directory Replication Model Works

–

Also check out this blog post to find the script version to check latency/convergence of the SYSVOL

–

UPDATE: A newer version of this blog post and the PowerShell script can be found here.

–

Cheers,

Jorge

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* This posting is provided "AS IS" with no warranties and confers no rights!

* Always evaluate/test yourself before using/implementing this!

* DISCLAIMER:

https://jorgequestforknowledge.wordpress.com/disclaimer/

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############### Jorge’s Quest For Knowledge #############

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http://JorgeQuestForKnowledge.wordpress.com/ ########

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