For pesky 3G/4G home router that often drops its mobile data connectivity due to inactivity

loop-test-connection.ps1

#Requires -Version 7.0

Param(
    [Float] $Delay = 1,
    [Float] $FailureDelay = 1,
    [Int32] $BufferSize = 1
)

[System.Threading.Thread]::CurrentThread.CurrentCulture = 'en-GB'

$Delay = [Math]::Round($Delay, 1)
$FailureDelay = [Math]::Round($FailureDelay, 1)

If ($Delay -lt 0.1) {
    "Delay cannot be less than 0.1 seconds."
    Exit 1
}

if ($FailureDelay -lt 0.1) {
    "Failure delay cannot be less than 0.1 seconds."
    Exit 1
}

If ($BufferSize -lt 1) {
    "Buffer size cannot be less than 1 byte."
    Exit 1
}

# Targets do not have to be DNS IPs, but they are chosen due to simplicity
$Targets = @(
    # Cloudflare DNS
    "1.1.1.1",
    "1.0.0.1",
    # Cloudflare DNS (No Malware)
    "1.1.1.2",
    "1.0.0.2",
    # Cloudflare DNS (No Malware/Adult)
    "1.1.1.3",
    "1.0.0.3",
    # Google DNS
    "8.8.8.8",
    "8.8.4.4",
    # OpenDNS
    "208.67.222.222",
    "208.67.220.220",
    # OpenDNS Family
    "208.67.222.123",
    "208.67.220.123",
    # OpenDNS Sandbox
    "208.67.220.2",
    "208.67.222.2"
)

"Test-Connection (Targets: {0:D}, Delay: {1:N1}s, Failure Delay: {2:N1}s Buffer Size: {3:D}B)" -F $Targets.Count, $Delay, $FailureDelay, $BufferSize

If ($Targets.Count -lt 1) {
    Exit 1
}

If ($Targets.Count -gt 1) {
    $TargetsA = [System.Collections.ArrayList] $Targets
    $TargetsB = [System.Collections.ArrayList] @()
}

While ($True) {
    # Ensure it loops through all targets in random order before going through them all over again
    If ($Targets.Count -gt 1) {
        If ($TargetsA.Count -eq 0) {
            $TargetsA = $TargetsB
            $TargetsB = [System.Collections.ArrayList] @()
        }
        If ($TargetsA.Count -eq 1) {
            $Index = 0
        } Else {
            $Index = Get-Random -Minimum 0 -Maximum ($TargetsA.Count - 1)
        }
        $Target = $TargetsA[$Index]
        $TargetsB.Add($Target) | Out-Null
        $TargetsA.RemoveAt($Index)
    } Else {
        $Target = $Targets[0]
    }

    $DateNow = (Get-Date -Format "hh:mm:ss tt").ToUpper()
    Write-Host -NoNewLine ("[{0}] {1} -> " -F $DateNow, $Target)

    $TestResult = Test-Connection -TargetName $Target -Count 1 -BufferSize $BufferSize
    If ($TestResult.Status -eq "Success") {
        "{0} ({1}ms)" -F $TestResult.Status, $TestResult.Latency
        Start-Sleep -Seconds $Delay
    } Else {
        $TestResult.Status
        Start-Sleep -Seconds $FailureDelay
    }
}