<#
 This script will compare the

 Shay Levy posted the Get the AD site name of a computer function here:
 http://www.powershellmagazine.com/2013/04/23/pstip-get-the-ad-site-name-of-a-computer/

 Microsoft posted a method for retrieving the DynamicSiteName here:
 Problem retrieving Value for DynamicSiteName from Registry using PS: http://support.microsoft.com/kb/2801452

  https://github.com/joethemongoose/PowerCLI/blob/master/Export-VMs-With-SiteCode.ps1

#>

#-------------------------------------------------------------
# Get the script path
$ScriptPath = { Split-Path $MyInvocation.ScriptName }
$OnlineFile = $(&$ScriptPath) + "\SiteNameConsistency-online.csv"
$OfflineFile = $(&$ScriptPath) + "\SiteNameConsistency-offline.csv"

#-------------------------------------------------------------

Import-Module ActiveDirectory

# Get Domain Controllers
$Computers = Get-ADDomainController -Filter * | Sort-Object Name

# Get All Servers
#$Computers = Get-ADComputer -Filter * -Properties Name,Operatingsystem | Where-Object {$_.Operatingsystem -like "*server*"} | Sort-Object Name

# Get All Authorized DHCP Servers
$defaultNC = ([ADSI]"LDAP://RootDSE").defaultNamingContext.Value
$configurationNC = "cn=configuration," + $defaultNC
$AuthorizedDHCPServers = Get-ADObject -SearchBase $configurationNC -Filter "objectclass -eq 'dhcpclass' -AND Name -ne 'dhcproot'"

#-------------------------------------------------------------

function Get-ComputerSite($ComputerName) {
    $site = nltest /server:$ComputerName /dsgetsite 2>$null
    if ($LASTEXITCODE -eq 0) { $site[0] }
}

function Get-ComputerSiteValue($ComputerName, $Value) {
    $ValueData = ""
    $key = "System\CurrentControlSet\Services\NetLogon\Parameters"
    $type = [Microsoft.Win32.RegistryHive]::LocalMachine
    Try {
        $regKey = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey($type, $ComputerName)
        $regKey = $regKey.OpenSubKey($key)
        $ValueData = $regKey.GetValue($($Value)).Split([char]0)[0]
    }
    Catch {
        Write-Host -ForegroundColor Red "- $($Value): Could Not Connect to Remote Registry!"
    }
    $ValueData
}

$onlinearray = @()
$offlinearray = @()

ForEach ($Computer in $Computers) {
    $ComputerError = "$false"
    $ComputerName = $Computer.Name
    if (Test-Connection -Cn $Computer.Name -BufferSize 16 -Count 1 -ea 0 -quiet) {
        Write-Host -ForegroundColor Green "Checking Site for $ComputerName"
        $ComputerSite = Get-ComputerSite $ComputerName
        $ComputerDynamicSiteName = Get-ComputerSiteValue $ComputerName DynamicSiteName
        $ComputerSiteName = Get-ComputerSiteValue $ComputerName SiteName
        $DynamicSiteName = $False
        $SiteName = $False

        If ($ComputerDynamicSiteName -ne "") { $DynamicSiteName = $True }
        If ($ComputerSiteName -ne "") { $SiteName = $True }
        If ($SiteName -eq $True) {
            If ($ComputerSite -eq $ComputerSiteName) {
                Write-Host -ForegroundColor Green "- Sites match"
            }
            Else {
                Write-Host -ForegroundColor Red "- Sites do not match"
            }
        }
        ElseIf ($DynamicSiteName -eq $True) {
            If ($ComputerSite -eq $ComputerDynamicSiteName) {
                Write-Host -ForegroundColor Green "- Sites match"
            }
            Else {
                Write-Host -ForegroundColor Red "- Sites do not match"
            }
        }
        Else {
            Write-Host -ForegroundColor Red "- Both the DynamicSiteName and SiteName registry values are missing."
        }
    }
    Else {
        $ComputerError = "$true"
        $ErrorDescription = "Unable to ping server"
        Write-Host -ForegroundColor Red "$ComputerName is offline"
    }
    if ($ComputerError -eq $true) {
        $outputbad = New-Object PSObject
        $outputbad | Add-Member NoteProperty ComputerName $ComputerName
        $outputbad | Add-Member NoteProperty ErrorDescription $ErrorDescription
        $offlinearray += $outputbad
    }
}
$onlinearray | export-csv -notype "$OnlineFile"
$offlinearray | export-CSV -notype "$OfflineFile"

# Remove the quotes
(Get-Content "$OnlineFile") | ForEach-Object { $_ -replace '"', "" } | out-file "$OnlineFile" -Force -Encoding ascii
(Get-Content "$OfflineFile") | ForEach-Object { $_ -replace '"', "" } | out-file "$OfflineFile" -Force -Encoding ascii