Network-DnsCleanup.ps1

# Network DNS Configuration Cleanup Tool
# Safely detects and fixes broken DNS server configurations
# Author: AI Assistant  
# Date: 2025-10-10

Write-Host "=== DNS Configuration Cleanup Tool ===" -ForegroundColor Cyan
Write-Host "This tool will safely check and fix DNS configuration issues." -ForegroundColor Gray
Write-Host ""

# Check for broken DNS servers
Write-Host "Analyzing DNS configuration..." -ForegroundColor Yellow
$problemDns = @()
$dnsConfigs = Get-DnsClientServerAddress -AddressFamily IPv4 | Where-Object { $_.ServerAddresses.Count -gt 0 }

foreach ($config in $dnsConfigs) {
    $interfaceStatus = (Get-NetAdapter -Name $config.InterfaceAlias -ErrorAction SilentlyContinue).Status
    Write-Host "Checking $($config.InterfaceAlias) (Status: $interfaceStatus)" -ForegroundColor Gray
    
    foreach ($dns in $config.ServerAddresses) {
        try {
            Write-Host "  Testing DNS $dns..." -ForegroundColor Gray -NoNewline
            $null = Resolve-DnsName -Name "google.com" -Server $dns -Type A -ErrorAction Stop -TimeoutInSeconds 3
            Write-Host " WORKING" -ForegroundColor Green
        } catch {
            Write-Host " FAILED" -ForegroundColor Red
            $problemDns += @{
                Interface = $config.InterfaceAlias
                Status = $interfaceStatus  
                DNS = $dns
            }
        }
    }
}

if ($problemDns.Count -eq 0) {
    Write-Host "`n✓ All DNS servers are working properly!" -ForegroundColor Green
    Write-Host "No cleanup needed." -ForegroundColor White
    exit 0
}

# Show problems and ask for permission to fix
Write-Host "`n⚠ Found $($problemDns.Count) broken DNS configuration(s):" -ForegroundColor Yellow
foreach ($problem in $problemDns) {
    Write-Host "  • $($problem.DNS) on $($problem.Interface) ($($problem.Status))" -ForegroundColor Red
}

Write-Host "`nWould you like to fix these automatically? This will:" -ForegroundColor Cyan
Write-Host "  • Clear broken DNS from disconnected interfaces" -ForegroundColor White  
Write-Host "  • Replace broken DNS on active interfaces with Google DNS (8.8.8.8)" -ForegroundColor White
Write-Host ""

$consent = Read-Host "Proceed with cleanup? (y/N)"
if ($consent -notmatch '^[Yy]') {
    Write-Host "Cleanup cancelled. No changes made." -ForegroundColor Gray
    exit 0
}

# Perform safe cleanup
Write-Host "`nPerforming DNS cleanup..." -ForegroundColor Cyan
$fixed = 0

foreach ($problem in $problemDns) {
    Write-Host "Fixing $($problem.Interface)..." -ForegroundColor Yellow
    
    if ($problem.Status -eq "Up") {
        # Active interface - replace with reliable DNS
        try {
            Set-DnsClientServerAddress -InterfaceAlias $problem.Interface -ServerAddresses @("8.8.8.8", "8.8.4.4")
            Write-Host "  ✓ Set reliable DNS on $($problem.Interface)" -ForegroundColor Green
            $fixed++
        } catch {
            Write-Host "  ✗ Failed to fix $($problem.Interface): $($_.Exception.Message)" -ForegroundColor Red
        }
    } else {
        # Disconnected interface - clear DNS
        try {
            Set-DnsClientServerAddress -InterfaceAlias $problem.Interface -ResetServerAddresses  
            Write-Host "  ✓ Cleared DNS from disconnected $($problem.Interface)" -ForegroundColor Green
            $fixed++
        } catch {
            Write-Host "  ✗ Failed to clear $($problem.Interface): $($_.Exception.Message)" -ForegroundColor Red
        }
    }
}

Write-Host "`n🎯 Cleanup complete! Fixed $fixed of $($problemDns.Count) issues." -ForegroundColor Green
Write-Host "Run Network-DetailedDiagnostics.ps1 again to verify the fixes." -ForegroundColor Cyan

if ($Host.Name -eq "ConsoleHost") {
    Write-Host "`nPress Enter to close..." -ForegroundColor Gray
    Read-Host
}