Count-AllDomainControllers

##########################################
# AUTHOR   : Ryan Mutschler
# DATE     : 8-15-2014
# EDIT     : 8-15-2014
# COMMENT  : Domain Controller Counter
# This script prompts for a list of domains and counts the number of domain controllers in each domain
# Compatible with all PowerShell versions 
# Created with assistance from claude.ai
#
# VERSION  : 1    (Initial release)
##########################################


function Get-DomainControllers {
    param (
        [Parameter(Mandatory=$true)]
        [string]$DomainName
    )

    try {
        Write-Host "Searching for domain controllers in $DomainName..." -ForegroundColor Cyan
        
        # Use .NET DirectoryServices to query the domain
        $context = New-Object System.DirectoryServices.ActiveDirectory.DirectoryContext("Domain", $DomainName)
        $domain = [System.DirectoryServices.ActiveDirectory.Domain]::GetDomain($context)
        
        # Get all domain controllers
        $domainControllers = $domain.DomainControllers
        
        # Return the domain controllers
        return $domainControllers
    }
    catch [System.DirectoryServices.ActiveDirectory.ActiveDirectoryServerDownException] {
        Write-Host "Error: Cannot connect to domain $DomainName. The domain may not exist or is not accessible." -ForegroundColor Red
        return $null
    }
    catch {
        $errorMessage = $_.Exception.Message
        Write-Host ("Error occurred while querying domain " + $DomainName + ": " + $errorMessage) -ForegroundColor Red
        return $null
    }
}

function Main {
    Clear-Host
    Write-Host "=========================================" -ForegroundColor Green
    Write-Host "      Domain Controller Counter Tool     " -ForegroundColor Green
    Write-Host "=========================================" -ForegroundColor Green
    Write-Host ""
    
    # Prompt for domains
    Write-Host "Enter domain names (one per line). Press Enter on a blank line when finished:" -ForegroundColor Yellow
    $domainList = @()
    
    while ($true) {
        $domain = Read-Host
        if ([string]::IsNullOrWhiteSpace($domain)) {
            break
        }
        $domainList += $domain
    }
    
    # Validate that domains were entered
    if ($domainList.Count -eq 0) {
        Write-Host "No domains entered. Exiting script." -ForegroundColor Red
        return
    }
    
    Write-Host ""
    Write-Host "=========================================" -ForegroundColor Green
    Write-Host "       Domain Controller Results         " -ForegroundColor Green
    Write-Host "=========================================" -ForegroundColor Green
    
    # Create a result table
    $results = @()
    
    # Process each domain
    foreach ($domainName in $domainList) {
        $dcs = Get-DomainControllers -DomainName $domainName
        
        if ($null -ne $dcs) {
            $dcCount = $dcs.Count
            
            # Create result object
            $resultObj = New-Object PSObject -Property @{
                DomainName = $domainName
                DCCount = $dcCount
                Status = "Connected"
            }
            
            $results += $resultObj
            
            # Display domain controllers
            Write-Host ""
            Write-Host "Domain: $domainName - $dcCount Domain Controller(s) found" -ForegroundColor Green
            
            if ($dcCount -gt 0) {
                foreach ($dc in $dcs) {
                    Write-Host "  - $($dc.Name) (Site: $($dc.SiteName))" -ForegroundColor White
                }
            }
        }
        else {
            # Create result object for failed connection
            $resultObj = New-Object PSObject -Property @{
                DomainName = $domainName
                DCCount = 0
                Status = "Failed to connect"
            }
            
            $results += $resultObj
        }
    }
    
    # Display summary
    Write-Host ""
    Write-Host "=========================================" -ForegroundColor Green
    Write-Host "               Summary                   " -ForegroundColor Green
    Write-Host "=========================================" -ForegroundColor Green
    
    $format = "{0,-30} {1,-10} {2,-20}"
    Write-Host ($format -f "Domain", "DC Count", "Status") -ForegroundColor Yellow
    Write-Host ($format -f "------", "--------", "------") -ForegroundColor Yellow
    
    foreach ($result in $results) {
        $statusColor = if ($result.Status -eq "Connected") { "Green" } else { "Red" }
        Write-Host ($format -f $result.DomainName, $result.DCCount, $result.Status) -ForegroundColor $statusColor
    }
    
    Write-Host ""
    Write-Host "Script completed." -ForegroundColor Cyan
}

# Run the main function
Main