DNS Ping Test Utility PowerShell Script

<#
.SYNOPSIS
    DNS Ping Test Utility

.DESCRIPTION
    This script allows the user to choose from a list of popular DNS servers (e.g., Google, Cloudflare, OpenDNS, etc.)
    and then performs either continuous or fixed-count ping tests to verify network connectivity.
    Users can configure the interval between pings and optionally log the results to a file for further analysis.
    
.NOTES
    Press Ctrl+C to exit continuous ping mode.
#>

# Define a list of DNS providers.
$dnsProviders = @(
    [PSCustomObject]@{Name="Google DNS";       IP="8.8.8.8"},
    [PSCustomObject]@{Name="Cloudflare DNS";   IP="1.1.1.1"},
    [PSCustomObject]@{Name="OpenDNS";          IP="208.67.222.222"},
    [PSCustomObject]@{Name="Quad9 DNS";        IP="9.9.9.9"},
    [PSCustomObject]@{Name="Level3 DNS";       IP="4.2.2.2"}
)

# Display the DNS server options.
Write-Host "Select a DNS server to ping:" -ForegroundColor Cyan
for ($i = 0; $i -lt $dnsProviders.Count; $i++) {
    Write-Host ("{0}. {1} ({2})" -f ($i + 1), $dnsProviders[$i].Name, $dnsProviders[$i].IP)
}

# Prompt the user to choose a DNS server.
[int]$choice = Read-Host "Enter the number corresponding to your choice"
if ($choice -lt 1 -or $choice -gt $dnsProviders.Count) {
    Write-Error "Invalid selection. Exiting."
    exit
}

$selectedDNS = $dnsProviders[$choice - 1]
Write-Host "You selected: $($selectedDNS.Name) ($($selectedDNS.IP))" -ForegroundColor Green

# Ask if the user wants a fixed number of pings or continuous ping.
$pingCountInput = Read-Host "Enter number of pings (or press Enter for continuous ping)"
if ($pingCountInput -match '^\d+$') {
    $pingCount = [int]$pingCountInput
    $isContinuous = $false
} else {
    $isContinuous = $true
}

# Ask for the interval between pings in seconds.
$intervalInput = Read-Host "Enter interval in seconds between pings (default is 1 second)"
if ([string]::IsNullOrWhiteSpace($intervalInput)) {
    $interval = 1
} else {
    $interval = [double]$intervalInput
}

# Ask if the user wants to log the results to a file.
$logChoice = Read-Host "Do you want to log results to a file? (Y/N)"
$logEnabled = $false
if ($logChoice -match '^[Yy]') {
    $logEnabled = $true
    $logFile = Read-Host "Enter log file path (or press Enter for default 'DNSPingLog.txt')"
    if ([string]::IsNullOrWhiteSpace($logFile)) {
        $logFile = "DNSPingLog.txt"
    }
    Write-Host "Logging enabled. Results will be saved to $logFile" -ForegroundColor Green
}

# Initialize an array to store successful ping response times if a fixed ping count is specified.
if (-not $isContinuous) {
    $results = @()
}

Write-Host "Starting ping test to $($selectedDNS.IP)..." -ForegroundColor Cyan

# Function to log output if logging is enabled.
function Log-Output {
    param (
        [string]$message
    )
    if ($logEnabled) {
        $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
        Add-Content -Path $logFile -Value "[$timestamp] $message"
    }
}

# Run the ping test.
if ($isContinuous) {
    Write-Host "Press Ctrl+C to stop continuous ping."
    while ($true) {
        try {
            $pingResult = Test-Connection -ComputerName $selectedDNS.IP -Count 1 -ErrorAction SilentlyContinue
            $timestamp = Get-Date -Format "HH:mm:ss"
            if ($pingResult) {
                $replyTime = $pingResult.ResponseTime
                $output = "[$timestamp] Ping $($i)/$($pingCount): Reply from $($selectedDNS.IP): time = $replyTime ms"
            } else {
                $output = "[$timestamp] Ping $($i)/$($pingCount): Request timed out for $($selectedDNS.IP)."
            }
            Write-Host $output
            Log-Output -message $output
        }
        catch {
            Write-Host "An error occurred: $_"
            Log-Output -message "Error: $_"
        }
        Start-Sleep -Seconds $interval
    }
} else {
    for ($i = 1; $i -le $pingCount; $i++) {
        try {
            $pingResult = Test-Connection -ComputerName $selectedDNS.IP -Count 1 -ErrorAction SilentlyContinue
            $timestamp = Get-Date -Format "HH:mm:ss"
            if ($pingResult) {
                $replyTime = $pingResult.ResponseTime
                $output = "[$timestamp] Ping $($i)/$($pingCount): Reply from $($selectedDNS.IP): time = $replyTime ms"
                $results += $replyTime
            } else {
                $output = "[$timestamp] Ping $($i)/$($pingCount): Request timed out for $($selectedDNS.IP)."
            }
            Write-Host $output
            Log-Output -message $output
        }
        catch {
            Write-Host "An error occurred: $_"
            Log-Output -message "Error: $_"
        }
        Start-Sleep -Seconds $interval
    }
    
    # Provide summary statistics for the fixed-count ping test.
    if ($results.Count -gt 0) {
        $avgTime = [Math]::Round(($results | Measure-Object -Average).Average, 2)
        Write-Host "`nPing test completed. Average response time: $avgTime ms" -ForegroundColor Green
        Log-Output -message "Ping test completed. Average response time: $avgTime ms"
    } else {
        Write-Host "`nPing test completed. No successful pings." -ForegroundColor Yellow
        Log-Output -message "Ping test completed. No successful pings."
    }
}