MSP - Quick Domain Controller Checks

qiuck_ad_check.ps1

#
# Invoke-Expression (New-Object Net.WebClient).DownloadString('https://gist.githubusercontent.com/tanfwc/e55e67e18079765cb630d9dc7b436681/raw/6a61bd2f4d3cb8ccbe7a05c090d59cf4f3490cfe/qiuck_ad_check.ps1')


# Function to test network connectivity to the Domain Controller
function Test-NetworkConnectivity {
    Write-Host "`nTesting Network Connectivity..." -ForegroundColor Cyan
    $DomainName = $env:USERDNSDOMAIN
    if (-not $DomainName) {
        Write-Host "This computer is NOT joined to a domain." -ForegroundColor Red
        return
    }
    $DomainController = (nltest /dsgetdc:$DomainName | Select-String "DC:").ToString().Split(":")[1].Trim()
    if ($DomainController) {
        Write-Host "Domain Controller detected: $DomainController" -ForegroundColor Green
        $PingResult = Test-Connection -ComputerName $DomainController -Count 2 -Quiet
        if ($PingResult) {
            Write-Host "Network connectivity to Domain Controller is OK." -ForegroundColor Green
        } else {
            Write-Host "Network connectivity to Domain Controller FAILED." -ForegroundColor Red
        }
    } else {
        Write-Host "Could not detect a Domain Controller." -ForegroundColor Red
    }
}

# Function to check computer domain join status
function Test-DomainJoinStatus {
    Write-Host "`nChecking Domain Join Status..." -ForegroundColor Cyan
    $DomainName = $env:USERDNSDOMAIN
    if ($DomainName) {
        Write-Host "This computer is joined to the domain: $DomainName" -ForegroundColor Green
    } else {
        Write-Host "This computer is NOT joined to any domain." -ForegroundColor Red
    }
}

# Function to test Kerberos Authentication
function Test-Kerberos {
    Write-Host "`nChecking Kerberos Authentication..." -ForegroundColor Cyan
    try {
        klist.exe | Out-Null
        Write-Host "Kerberos tickets detected. Authentication is working." -ForegroundColor Green
    } catch {
        Write-Host "Kerberos ticket check FAILED. Ensure the system time is synchronized." -ForegroundColor Red
    }
}

# Function to check system time synchronization
function Test-TimeSync {
    Write-Host "`nChecking System Time Synchronization..." -ForegroundColor Cyan
    $W32Time = w32tm /query /status | Select-String "Source"
    if ($W32Time) {
        Write-Host "Time Source: $W32Time" -ForegroundColor Green
    } else {
        Write-Host "Time synchronization check FAILED. Check NTP settings." -ForegroundColor Red
    }
}

# Main Execution
Write-Host "=== Active Directory Connectivity Health Check ===`n" -ForegroundColor Yellow
Test-DomainJoinStatus
Test-NetworkConnectivity
Test-Kerberos
Test-TimeSync
Write-Host "`n=== Check Completed ===" -ForegroundColor Yellow