Log status data

February 17, 2015 · View on GitHub

<#---------------------------------------------------------------------------------------------------- Release Notes:

v1.4: 
    Author: Jared Poeppelman, Microsoft
    First version published on TechNet Script Gallery

----------------------------------------------------------------------------------------------------#>

function Test-Command { Param([string]$Command)

Try {Invoke-Expression $Command} 
Catch [System.Exception] {If ($Error.FullyQualifiedErrorId -eq 'CommandNotFoundException') {Return $false}} 
Return $true
}

function Test-RpcToHost { Param([string]$Hostname)

Try {$RpcPingResult = rpcping.exe -s $Hostname} # Attempt to RPCPING the target host

# Check for RPCPING.exe command and execution errors
Catch [System.Exception] 
    {
    If ($Error.FullyQualifiedErrorId -eq 'CommandNotFoundException') {Write-Host -ForegroundColor Red "The 'RPCPING.exe' utility is not available. Install it and/or add its location to the path and retry... exiting."; Exit}
    Write-Host -ForegroundColor Red "An unknown error occurred when attempting to execute 'RPCPING.exe'... exiting."; Exit
    } 

# Check output of RPCPING for success
If ($RpcPingResult -like "*Completed*") {Return (New-Object -TypeName PSObject -Property @{'Success'=$true; 'Message'="$Hostname - RPC connectivity successful."})}
    
# Check output of RPCPING for exceptions
If ($RpcPingResult -like "*Exception 5*")    {Return (New-Object -TypeName PSObject -Property @{'Success'=$false; 'Message'="$Hostname - Access is denied. Ensure your credentials have the required rights on the target host."})}
If ($RpcPingResult -like "*Exception 1722*") {Return (New-Object -TypeName PSObject -Property @{'Success'=$false; 'Message'="$Hostname - RPC server unavailable. Check firewall rules and name resolution for the target host."})}
If ($RpcPingResult -like "*Exception*")      {Return (New-Object -TypeName PSObject -Property @{'Success'=$false; 'Message'="$Hostname - RPC to the target host failed for an unknown reason."})}
}

function Replicate-ADSingleObject { Param([string]TargetDC,[string]TargetDC, [string]SourceDC, [string]$ObjectDN)

Try {$RepAdminResult = repadmin.exe /replsingleobj $TargetDC $SourceDC $ObjectDN} # Attempt REPADMIN 

# Check for REPADMIN.exe command and execution errors
Catch [System.Exception] 
    {
    If ($Error.FullyQualifiedErrorId -eq 'CommandNotFoundException') {Write-Host -ForegroundColor Red "The 'REPADMIN.exe' utility is not available. Install it and/or add its location to the path and retry... exiting."; Exit}
    Write-Host -ForegroundColor Red "An unknown error occurred when attempting to execute 'REPADMIN.exe'... exiting."; Exit
    }

# Check output of REPADMIN for success
If ($RepAdminResult -like "*Successfully replicated object*") {Return (New-Object -TypeName PSObject -Property @{'Success'=$true; 'Message'="$ObjectDN - Successfully replicated from $SourceDC to $TargetDC."})}

# Check output of REPADMIN for exceptions
If ($RepAdminResult -like "*Exception 5*")    {Return (New-Object -TypeName PSObject -Property @{'Success'=$false; 'Message'="$ObjectDN - $SourceDC access is denied. Ensure your credentials have the required rights on the target host."})}
If ($RepAdminResult -like "*Exception 1722*") {Return (New-Object -TypeName PSObject -Property @{'Success'=$false; 'Message'="$ObjectDN - $SourceDC server unavailable. Check firewall rules and name resolution for the target host."})}
If ($RepAdminResult -like "*Exception*")      {Return (New-Object -TypeName PSObject -Property @{'Success'=$false; 'Message'="$ObjectDN - Failed to replicate from $SourceDC to $TargetDC for an unknown reason."})}
}

function Shuffle-Array { Param([Array] a)a) rnd=(New-Object System.Random) For(i=0;i=0;i -lt a.Length;a.Length;i+=1) { newpos=newpos=i + rnd.Next(rnd.Next(a.Length - i);i); tmp=a[a[i]; a[a[i]=a[a[newpos]; a[a[newpos]=tmp } Return a }

function New-ComplexPassword { Param([string]Username,[int]Username, [int]PasswordLength)

# Keep the password length within bounds
If ($PasswordLength -lt 8) {$PasswordLength = 8}
If ($PasswordLength -gt 28) {$PasswordLength = 28}

# Define base characters for complex password and avoid ambiguous characters like I,i,1,L,l,O,o,0, etc.
$UpperAlpha = @('A','B','C','D','E','F','G','H','J','K','M','N','P','Q','R','S','T','U','V','W','X','Y','Z')
$LowerAlpha = @(); ForEach ($i in $UpperAlpha) {$LowerAlpha += $i.ToLower()}
$Numerics = @('2','3','4','5','6','7','8','9')
$SpecialChars = @('~','!','@','#','$','%','^','&','*','_','+','=','.','?')

# Remove characters of the username to avoid possible conflicts 
$UpperAlpha = $UpperAlpha | Where-Object {($Username.ToCharArray()) -notcontains $_}
$LowerAlpha = $LowerAlpha | Where-Object {($Username.ToCharArray()) -notcontains $_}

[char[]]$ComplexPassword

# Add random characters to our password until required length is reached
For ($i=1; $i -le $PasswordLength; $i++) 
	{
	If (($i % 4) -eq 0) {$ComplexPassword += $UpperAlpha | Get-Random}
	If (($i % 4) -eq 1) {$ComplexPassword += $LowerAlpha | Get-Random}
	If (($i % 4) -eq 2) {$ComplexPassword += $Numerics | Get-Random}
	If (($i % 4) -eq 3) {$ComplexPassword += $SpecialChars | Get-Random}
	}

# Shuffle the password characters, so the type positions are not predictable and return it
Return ((Shuffle-Array $ComplexPassword.ToCharArray()) -join "")
}

function Reset-KrbtgtKey { Param([string]$Server)

Try {Set-ADAccountPassword -Identity (Get-ADUser krbtgt -Server $Server).DistinguishedName -Server $Server -Reset -NewPassword (ConvertTo-SecureString ((New-ComplexPassword krbtgt 22).ToString()) -AsPlainText -Force)}
Catch 
    {
    If (($Error.FullyQualifiedErrorId -eq 'ActiveDirectoryCmdlet:System.UnauthorizedAccessException,Microsoft.ActiveDirectory.Management.Commands.SetADAccountPassword') -and ($Error.CategoryInfo -like "*PermissionDenied*"))
        {Return (New-Object -TypeName PSObject -Property @{'Success'=$false; 'Message'='Krbtgt key reset failed due to insufficient permissions.'})}
    Else {Return (New-Object -TypeName PSObject -Property @{'Success'=$false; 'Message'='Krbtgt key reset failed for an unknown reason.'})}
    }
Return (New-Object -TypeName PSObject -Property @{'Success'=$true; 'Message'='Krbtgt key reset successfully.'})
}

<#---------------------------------------------------------------------------------------------------- Initialize ----------------------------------------------------------------------------------------------------#> #cls Set-Location (Split-Path MyInvocation.MyCommand.Path) # Set the path of the script as the working directory TimeStamp = Get-Date -Format o | foreach {_ -replace ":", "."} # Timestamp for logfile LogFile = "Reset-KrbtgtKey_TimeStamp.log" # Logfile Status = New-Object -TypeName PSObject # Custom object for status information

<#---------------------------------------------------------------------------------------------------- Display menu options to user ----------------------------------------------------------------------------------------------------#> $ScriptDescription = @' This script can be used to perform a single reset of the krbtgt key that is shared by all writable domain controllers in the domain in which it is run.

This script has 3 modes: '@ $Mode1Description = @'

  • Mode 1 is Informational Mode. This mode is safe to run at any time and makes no changes to the environment. It will analyze the environment and check for issues that may impact the successful execution of Mode 2 or Mode 3. '@ $Mode2Description = @'

  • Mode 2 is Estimation Mode. This mode will perform all the analysis and checks included in Mode 1. It will also initiate a single object replication of the krbtgt object from the PDC emulator DC to every writable domain controller that is reachable. This replication is not to replicate changes (no changes will be made). Instead, this replication is performed so that it can be measured and an estimate provided for the impact duration of Mode 3. '@ $Mode3Description = @'

  • Mode 3 is Reset Mode. This mode will perform all the analysis and checks included in Mode 1. It will also perform a single reset of the krbtgt key on the PDC emulator DC. If the krbtgt reset is successful, it will automatically initiate a single object replication of krbtgt from the PDC emulator DC to every writable domain controller that is reachable. Once the replication is complete, the total impact time will be displayed. During the impact duration of Mode 3 (estimated in Mode 2), the following impacts may be observed: '@ Mode3Impact1=@′−KerberosPACvalidationfailures:UntilthenewkrbtgtkeyisreplicatedtoallwritableDCsinthedomain,applicationswhichattemptKDCPACvalidationmayexperienceKDCPACvalidationfailures.ThisispossiblewhenaclientinonesiteisaccessingaKerberos−authenticatedapplicationthatisinadifferentsite.Ifthatapplicationisnotatrustedpartoftheoperatingsystem,itmayattempttovalidatethePACoftheclient′′sKerberosserviceticketagainsttheKDC(DC)initssite.IftheDCinitssitedoesnotyethavethenewkrbtgtkey,thisKDCPACvalidationwillfail.Thiswilllikelymanifestitselftotheclientasauthenticationerrorsforthatapplication.OnceallDCshavethenewkrbtgtkey,someaffectedclientsmayrecovergracefullyandresumefunctioningnormally.Ifnot,rebootingtheaffectedclient(s)willresolvetheissue.ThisissuemaynotoccurifthereplicationofthenewkrbtgtkeyistimelyandsuccessfulandnoapplicationsattemptKDCPACvalidationagainstanoutofsyncDCduringthattime.′@Mode3Impact1 = @' - Kerberos PAC validation failures: Until the new krbtgt key is replicated to all writable DCs in the domain, applications which attempt KDC PAC validation may experience KDC PAC validation failures. This is possible when a client in one site is accessing a Kerberos-authenticated application that is in a different site. If that application is not a trusted part of the operating system, it may attempt to validate the PAC of the client''s Kerberos service ticket against the KDC (DC) in its site. If the DC in its site does not yet have the new krbtgt key, this KDC PAC validation will fail. This will likely manifest itself to the client as authentication errors for that application. Once all DCs have the new krbtgt key, some affected clients may recover gracefully and resume functioning normally. If not, rebooting the affected client(s) will resolve the issue. This issue may not occur if the replication of the new krbtgt key is timely and successful and no applications attempt KDC PAC validation against an out of sync DC during that time. '@ Mode3Impact2 = @' - Kerberos TGS request failures: Until the new krbtgt key is replicated to all writable DCs in the domain, a client may experience Kerberos authentication failures. This is when a client in one site has obtained a Kerberos user ticket (TGT) from a DC that has the new krbtgt, but then subsequently attempts to obtain a service ticket via a TGS request against a DC in a different site. If that DC does not also have the new krbtgt key, it will not be able to decrypt the client''s TGT, which will result in a TGS request failure. This will manifest itself to the client as authenticate errors. However, it should be noted that this impact is very unlikely, because it is very unlikely that a client will attempt to obtain a service ticket from a different DC than the one from which their TGT was obtained, especially during the relatively short impact duration of Mode 3. '@ ScriptRecommendation=@′ItishighlyrecommendedthatMode1berunfirst,thenMode2,andthenMode3.′@ScriptRecommendation = @' It is highly recommended that Mode 1 be run first, then Mode 2, and then Mode 3. '@ Menu = @' In which mode do you wish to run the script?

    1 --- Informational Mode (no changes made; no replication triggered) 2 --- Estimation Mode (no changes made, but replication WILL BE triggered for estimation purposes) 3 --- Reset Mode (krbtgt WILL BE reset once, and replication WILL BE triggered) 0 --- Exit '@ $MenuPrompt = '(Enter 1-3, or 0 to exit)'

Write-Host '' Write-Host ScriptDescriptionWrite−Host−ForegroundColorGreenScriptDescription Write-Host -ForegroundColor Green Mode1Description Write-Host -ForegroundColor Yellow Mode2DescriptionWrite−Host−ForegroundColorRedMode2Description Write-Host -ForegroundColor Red Mode3Description Write-Host -ForegroundColor Cyan Mode3Impact1Write−Host−ForegroundColorCyanMode3Impact1 Write-Host -ForegroundColor Cyan Mode3Impact2 Write-Host '' Write-Host ScriptRecommendationWrite−Host′′Write−HostScriptRecommendation Write-Host '' Write-Host Menu Write-Host ''

Status∣Add−Member−MemberTypeNoteProperty−Name′ScriptMode′−Value(Read−HostStatus | Add-Member -MemberType NoteProperty -Name 'ScriptMode' -Value (Read-Host MenuPrompt) Write-Host ''

If ((Status.ScriptMode−lt1)−or(Status.ScriptMode -lt 1) -or (Status.ScriptMode -gt 3)) {Write-Host 'Invalid selection...exiting'; Exit} # Validate input

<#---------------------------------------------------------------------------------------------------- Perform pre-flight checks ----------------------------------------------------------------------------------------------------#> Write-Host 'Checking for script pre-requisites...' Status∣Add−Member−MemberTypeNoteProperty−Name′PreFlightPassed′−ValueStatus | Add-Member -MemberType NoteProperty -Name 'PreFlightPassed' -Value true Write-Host '' Write-Host ' Checking for ActiveDirectory Powershell module.....' -NoNewline If (Get-Module -List ActiveDirectory) {Write-Host -ForegroundColor Green 'PASSED'} Else {Status.PreFlightPassed=Status.PreFlightPassed = false; Write-Host -ForegroundColor Red 'FAILED'} Write-Host ' Checking if RPCPING.exe is installed and in the path.....' -NoNewline If (Test-Command rpcping.exe) {Write-Host -ForegroundColor Green 'PASSED'} Else {Status.PreFlightPassed=Status.PreFlightPassed = false; Write-Host -ForegroundColor Red 'FAILED'} Write-Host ' Checking if REPADMIN.exe is installed and in the path.....' -NoNewline If (Test-Command repadmin.exe) {Write-Host -ForegroundColor Green 'PASSED'} Else {Status.PreFlightPassed=Status.PreFlightPassed = false; Write-Host -ForegroundColor Red 'FAILED'} Write-Host '' If (Status.PreFlightPassed−neStatus.PreFlightPassed -ne true) {Write-Host -ForegroundColor Red "Pre-flight checks failed... exiting."; Exit}

<#---------------------------------------------------------------------------------------------------- Gather and analyze domain information ----------------------------------------------------------------------------------------------------#> Write-Host 'Gathering and analyzing target domain information...' Import-Module ActiveDirectory

$TargetDomain = Get-AdDomain | Select Name,DNSRoot,NetBIOSName,DomainMode,PDCEmulator

Write-Host '' Write-Host ' Domain NetBIOS name: ' -NoNewline; Write-Host -ForegroundColor Cyan TargetDomain.NetBIOSNameWrite−Host′DomainDNSname:′−NoNewline;Write−Host−ForegroundColorCyanTargetDomain.NetBIOSName Write-Host ' Domain DNS name: ' -NoNewline; Write-Host -ForegroundColor Cyan TargetDomain.DNSRoot Write-Host ' PDC emulator: ' -NoNewline; Write-Host -ForegroundColor Cyan TargetDomain.PDCEmulatorWrite−Host′DomainMode:′−NoNewline;Write−Host−ForegroundColorCyanTargetDomain.PDCEmulator Write-Host ' DomainMode: ' -NoNewline; Write-Host -ForegroundColor Cyan TargetDomain.DomainMode Write-Host ' Checking domain functional mode is ''Windows2008Domain'' or higher.....' -NoNewline

Status∣Add−Member−MemberTypeNoteProperty−Name′DomainModePassed′−Value(!((Status | Add-Member -MemberType NoteProperty -Name 'DomainModePassed' -Value (!((TargetDomain.DomainMode -eq 'Windows2000Domain') -or (TargetDomain.DomainMode−eq′Windows2003InterimDomain′)−or(TargetDomain.DomainMode -eq 'Windows2003InterimDomain') -or (TargetDomain.DomainMode -eq 'Windows2003Domain'))) If ($Status.DomainModePassed) {Write-Host -ForegroundColor Green 'PASSED'} Else {Write-Host -ForegroundColor Red 'FAILED'} Write-Host ''

<#---------------------------------------------------------------------------------------------------- Gather and analyze krbtgt information and Kerberos policy ----------------------------------------------------------------------------------------------------#> Write-Host 'Gathering and analyzing krbtgt information and Kerberos policy...' Write-Host ''

Krbtgt=Get−ADUserkrbtgt−PropertiesPasswordLastSet−ServerKrbtgt = Get-ADUser krbtgt -Properties PasswordLastSet -Server TargetDomain.PDCEmulator [xml]gpo=Get−GPOReport−Guid′31B2F340−016D−11D2−945F−00C04FB984F9′−ReportTypeXmlgpo = Get-GPOReport -Guid '{31B2F340-016D-11D2-945F-00C04FB984F9}' -ReportType Xml MaxTgtLifetimeHrs = ((gpo.gpo.Computer.ExtensionData | Where-Object {.name -eq 'Security'}).Extension.ChildNodes | Where-Object {_.Name -eq 'MaxTicketAge'}).SettingNumber MaxClockSkewMins = ((gpo.gpo.Computer.ExtensionData | Where-Object {.name -eq 'Security'}).Extension.ChildNodes | Where-Object {_.Name -eq 'MaxClockSkew'}).SettingNumber ExpirationTimeForNMinusOneTickets = ((Krbtgt.PasswordLastSet.AddHours(Krbtgt.PasswordLastSet.AddHours(MaxTgtLifetimeHrs)).AddMinutes(MaxClockSkewMins)).AddMinutes(MaxClockSkewMins)).AddMinutes(MaxClockSkewMins) # Doubling the clock skew to account for skew in both directions

Write-Host ' Krbtgt account: ' -NoNewline; Write-Host -ForegroundColor Cyan Krbtgt.DistinguishedNameWrite−Host′KrbtgtaccountpasswordlastsetonPDCemulator:′−NoNewline;Write−Host−ForegroundColorCyanKrbtgt.DistinguishedName Write-Host ' Krbtgt account password last set on PDC emulator: ' -NoNewline; Write-Host -ForegroundColor Cyan Krbtgt.PasswordLastSet Write-Host ' Kerberos maximum lifetime for user ticket (TGT lifetime): ' -NoNewline; Write-Host -ForegroundColor Cyan MaxTgtLifetimeHrs′hours′Write−Host′Kerberosmaximumtoleranceforcomputerclocksynchronization:′−NoNewline;Write−Host−ForegroundColorCyanMaxTgtLifetimeHrs 'hours' Write-Host ' Kerberos maximum tolerance for computer clock synchronization: ' -NoNewline; Write-Host -ForegroundColor Cyan MaxClockSkewMins 'minutes' Write-Host ' Checking if all tickets based on the previous (N-1) krbtgt key have expired.....' -NoNewline

Status∣Add−Member−MemberTypeNoteProperty−Name′NMinusOneTicketExpirationPassed′−Value(Status | Add-Member -MemberType NoteProperty -Name 'NMinusOneTicketExpirationPassed' -Value (ExpirationTimeForNMinusOneTickets -lt [DateTime]::Now) If ($Status.NMinusOneTicketExpirationPassed) {Write-Host -ForegroundColor Green 'PASSED'} Else {Write-Host -ForegroundColor Red 'FAILED'} Write-Host ''

<#---------------------------------------------------------------------------------------------------- Gather and analyze domain controller information ----------------------------------------------------------------------------------------------------#> Write-Host 'Gathering and analyzing writable domain controller information...' Write-Host ''

RwDcs=@()RwDcs = @() RwDcs = Get-ADDomainController -Filter {IsReadOnly -eq false} -Server TargetDomain.PDCEmulator | Select Name,Hostname,Domain,Site

Write-Host ' Checking RPC connectivity to domain controllers:' Status∣Add−Member−MemberTypeNoteProperty−Name′RpcToDCsPassed′−ValueStatus | Add-Member -MemberType NoteProperty -Name 'RpcToDCsPassed' -Value true

ForEach (DCinDC in RwDcs) { Write-Host ' Checking RPC connectivity to'$DC.Hostname'.....' -NoNewline

$DC | Add-Member -MemberType NoteProperty -Name 'IsPdcEmulator' -Value ($DC.Hostname -eq $TargetDomain.PDCEmulator)
$DC | Add-Member -MemberType NoteProperty -Name 'IsReachableViaRpc' -Value ((Test-RpcToHost $DC.Hostname).Success)

If (!$DC.IsReachableViaRpc) {$Status.RpcToDCsPassed = $false;  Write-Host -ForegroundColor Red 'FAILED'}
Else {Write-Host -ForegroundColor Green 'PASSED'}
}

If ($Status.RpcToDCsPassed) {Write-Host -ForegroundColor Green ' Check for RPC connectivity to writable domain controllers PASSED: All writable DCs were reachable.'} Else {Write-Host -ForegroundColor Red ' Check for RPC connectivity to writable domain controllers FAILED. One or more writable DCs was unreachable.'} Write-Host ''

<#---------------------------------------------------------------------------------------------------- MODES 2 AND 3 - Replicate krbtgt to all writable DCs that are reachable and generate an impact estimate ----------------------------------------------------------------------------------------------------#> If (Status.ScriptMode−gt1−andStatus.ScriptMode -gt 1 -and Status.PreFlightPassed -and Status.DomainModePassed−andStatus.DomainModePassed -and Status.RpcToDCsPassed) {
Write-Host 'Replicating krbtgt object to all writable domain controllers that are reachable...'

If ($Status.ScriptMode -eq 2)
    {
    Write-Host -ForegroundColor Yellow '   The krbtgt object replication WILL BE triggered if you proceed. Are you sure you wish to proceed?'
    If (!((Read-Host  '   (Enter ''Y'' to proceed or any other key to exit)').ToUpper() -eq 'Y')) {Write-Host -ForegroundColor Yellow '   Replication of krbtgt was skipped at the user''s request...exiting'; Exit}
    }

$ImpactStartTime = (Get-Date).ToUniversalTime()

########## THIS IS WHERE KRBTGT PASSWORD RESET OCCURS IN MODE 3 ##########

# Replicate krbtgt to appropriate DCs
$Status | Add-Member -MemberType NoteProperty -Name 'ReplicationCheckSucceeded' -Value $true
ForEach ($DC in $RwDcs)
    {
    Write-Host '      Replication of krbtgt from'$TargetDomain.PDCEmulator'to'$DC.Hostname'...' -NoNewline
    If ($DC.IsReachableViaRpc)
        {
        $ReplAttemptStart = (Get-Date).ToUniversalTime()
        If ((Replicate-ADSingleObject $DC.Hostname $TargetDomain.PDCEmulator $Krbtgt.DistinguishedName).Success) {Write-Host -ForegroundColor Green 'SUCCEEDED' -NoNewline}
        Else {$Status.ReplicationCheckSucceeded = $false;  Write-Host -ForegroundColor Red 'FAILED' -NoNewline}
        $ReplElapsedTime = ((Get-Date).ToUniversalTime() - $ReplAttemptStart)
        Write-Host -ForegroundColor Cyan '  Time:'$ReplElapsedTime
        }
    Else {Write-Host -ForegroundColor Yellow 'SKIPPED'}
    }
$TotalImpactTime = (Get-Date).ToUniversalTime() - $ImpactStartTime
Write-Host ''
$Status | Add-Member -MemberType NoteProperty -Name 'ImpactDurationEstimate' -Value $TotalImpactTime

If ($Status.ReplicationCheckSucceeded) {Write-Host -ForegroundColor Cyan 'The total duration of impact when running Mode 3 will be approximately:' $TotalImpactTime}
Else {Write-Host -ForegroundColor Red 'Single object replication failed to one or more writable domain controllers. All failures should be remediated before attempting Mode 3.'}
}

<#---------------------------------------------------------------------------------------------------- MODE 3 ONLY - Reset the krbtgt key and replicate to all writable DCs that are reachable ----------------------------------------------------------------------------------------------------#> If (Status.ScriptMode−eq3−andStatus.ScriptMode -eq 3 -and Status.PreFlightPassed -and Status.DomainModePassed−andStatus.DomainModePassed -and Status.RpcToDCsPassed -and $Status.ReplicationCheckSucceeded) {
Write-Host 'Resetting krbtgt key and replicating krbtgt object to all reachable domain controllers...' Write-Host ''

Write-Host -ForegroundColor Red '   WARNING!!! The krbtgt key WILL BE reset AND krbtgt object replication WILL BE triggered if you proceed. Are you sure you wish to proceed?'
Write-Host -ForegroundColor Red '   If you proceed, the impact duration of Mode 3 (described above) will begin and not end until all DCs obtained the new krbtgt key.'
If (!((Read-Host  '   (Enter ''Y'' to proceed or any other key to exit)').ToUpper() -eq 'Y')) {Write-Host -ForegroundColor Yellow '   The krbtgt reset and replication was skipped at the user''s request...exiting'; Exit}
Write-Host ''

If (!$Status.NMinusOneTicketExpirationPassed)
    {
    Write-Host -ForegroundColor Red '   The last change of the krbtgt key for this domain occurred: ' -NoNewline; Write-Host -ForegroundColor Cyan $Krbtgt.PasswordLastSet 'according to'$TargetDomain.PDCEmulator
    Write-Host -ForegroundColor Red '   and the domain Kerberos policy is configured with a maximum user ticket (TGT) lifetime of '-NoNewline; Write-Host -ForegroundColor Cyan $MaxTgtLifetimeHrs 'hours'
    Write-Host -ForegroundColor Red '   and a maximum tolerance for computer clock synchronization of ' -NoNewline; Write-Host -ForegroundColor Cyan $MaxClockSkewMins 'minutes'
    Write-Host -ForegroundColor Red '   That means that if you reset the krbtgt key again before ' -NoNewline; Write-Host -ForegroundColor Cyan $ExpirationTimeForNMinusOneTickets 
    Write-Host -ForegroundColor Red '   A major impact is very likely.  Are you sure you wish to proceed?'
    If (!((Read-Host  '   (Enter ''Y'' to proceed or any other key to exit)').ToUpper() -eq 'Y')) {Write-Host -ForegroundColor Yellow '   The krbtgt reset and replication was skipped at the user''s request...exiting'; Exit}
    Write-Host ''
    }

$ImpactStartTime = (Get-Date).ToUniversalTime() # Record start time

# Reset krbtgt password 
Write-Host -ForegroundColor Cyan '   Resetting krbtgt key.....' -NoNewline
$Status | Add-Member -MemberType NoteProperty -Name 'ResetSucceeded' -Value (Reset-KrbtgtKey $TargetDomain.PDCEmulator).Success
If ($Status.ResetSucceeded) {Write-Host -ForegroundColor Green 'SUCCEEDED'} 
Else {Write-Host -ForegroundColor Red 'FAILED'; Write-Host -ForegroundColor Red '   Krbtgt reset failed. Check to ensure you have sufficient rights to reset the krbtgt account. Replication will be skipped'}
Write-Host ''

# Replicate krbtgt to appropriate DCs
If ($Status.ResetSucceeded)
    {
    $Status | Add-Member -MemberType NoteProperty -Name 'PostResetReplicationSucceeded' -Value $true
    ForEach ($DC in $RwDcs)
        {
        Write-Host '      Replication of krbtgt from'$TargetDomain.PDCEmulator'to'$DC.Hostname'...' -NoNewline
        If ($DC.IsReachableViaRpc)
            {
            $ReplAttemptStart = (Get-Date).ToUniversalTime()
            If ((Replicate-ADSingleObject $DC.Hostname $TargetDomain.PDCEmulator $Krbtgt.DistinguishedName).Success) {Write-Host -ForegroundColor Green 'SUCCEEDED' -NoNewline}
            Else {$Status.PostResetReplicationSucceeded = $false;  Write-Host -ForegroundColor Red 'FAILED' -NoNewline}
            $ReplElapsedTime = ((Get-Date).ToUniversalTime() - $ReplAttemptStart)
            Write-Host -ForegroundColor Cyan '  Time:'$ReplElapsedTime
            }
        Else {Write-Host -ForegroundColor Yellow 'SKIPPED'}
        }
    $TotalImpactTime = (Get-Date).ToUniversalTime() - $ImpactStartTime
    $Status | Add-Member -MemberType NoteProperty -Name 'ImpactDuration' -Value $TotalImpactTime
    
    If ($Status.PostResetReplicationSucceeded) {Write-Host -ForegroundColor Cyan 'The total duration of impact when running mode 3 was:' $TotalImpactTime}
    Else {Write-Host -ForegroundColor Red 'Single object replication failed to one or more writable domain controllers.'}
    Write-Host ''

    # Validate krbtgt password last set is in sync with PDC emulator
    Write-Host '   Validating krbtgt password last set is in sync with PDC emulator...'
    $Status | Add-Member -MemberType NoteProperty -Name 'NewKrbtgtKeyReplValidationPassed' -Value $true
    $KrbtgtKeyLastSetOnPdc = (Get-ADUser krbtgt -Properties PasswordLastSet -Server $TargetDomain.PDCEmulator).PasswordLastSet
    Write-Host '      PDC emulator: Krbtgt account password last set on'$TargetDomain.PDCEmulator'.....' -NoNewline; Write-Host -ForegroundColor Cyan $KrbtgtKeyLastSetOnPdc
    ForEach ($DC in $RwDcs)
        {
        If (!$DC.IsPdcEmulator) 
            {
            Write-Host '      Checking krbtgt account password last set on '$DC.Hostname'.....' -NoNewline
            If (!$DC.IsReachableViaRpc) {Write-Host -ForegroundColor Yellow "SKIPPED"}
            Else 
                {
                $CouldConnect = $true
                Try {$KrbtgtKeyLastSetOnThisDc = (Get-ADUser krbtgt -Properties PasswordLastSet -Server $DC.Hostname).PasswordLastSet}
                Catch 
                    {If ($Error.FullyQualifiedErrorId -eq 'ActiveDirectoryServer:0,Microsoft.ActiveDirectory.Management.Commands.GetADUser') {$CouldConnect = $false}}
                If ($CouldConnect)
                    {
                    If ($KrbtgtKeyLastSetOnThisDc -ne $KrbtgtKeyLastSetOnPdc) {Write-Host -ForegroundColor Red "FAILED" -NoNewline; $Status.NewKrbtgtKeyReplValidationPassed = $false}
                    Else {Write-Host -ForegroundColor Green "PASSED" -NoNewline}
                    Write-Host -ForegroundColor Cyan '  Last set:' $KrbtgtKeyLastSetOnThisDc
                }
                Else {Write-Host -ForegroundColor Yellow "SKIPPED (could not connect to server)"}
                }
            }
        }
    }
Write-Host ''
If (!$Status.NewKrbtgtKeyReplValidationPassed) {Write-Host -ForegroundColor Red '   Check if krbtgt key on all writable domain controllers was in sync with PDC emulator FAILED. One or more reachable DCs was out of sync with the PDC emulator.'}
Else {Write-Host -ForegroundColor Green '   Check if krbtgt key on all writable domain controllers was in sync with PDC emulator PASSED. All reachable DCs were in sync with the PDC emulator..'}
Write-Host ''
}

If ((!Status.PreFlightPassed−or!Status.PreFlightPassed -or !Status.DomainModePassed -or !Status.RpcToDCsPassed)−or(Status.RpcToDCsPassed) -or (Status.ScriptMode -gt 1 -and !$Status.ReplicationCheckSucceeded)) {Write-Host -ForegroundColor Red 'One or more items failed. Resolve failures and retry.'}

Log status data

Status∣Out−File−FilePathStatus | Out-File -FilePath LogFile -Append Write-Host "Logged to file: $LogFile"