Send-ARPRequest

Send-ARPRequest.psm1

# Original code is written by earthdiver1
# https://qiita.com/earthdiver1/items/0b9c85a5f2c90ba51f7e
# Modified by mkht
function Send-ARPRequest {
    [CmdletBinding(PositionalBinding = $False)]
    [Alias('arping')]
    Param(
        [Parameter(Position = 0)]
        [String]$Target, # IP address of the target host
        
        [Parameter()]
        [String]$Source, # if you have multiple interfaces (optional, default value: 0 (all interfaces))
        
        [Parameter()]
        [Alias('n')]
        [UInt32]$Count = 4, # the number of ARP requests to send (optional, default value: 4)
        
        [Parameter()]
        [UInt32]$Interval = 1 # the interval between ARP requests, in seconds (optional, default value: 1)
    )

    if (-not $Target) {
        Write-Output 'Usage: arping <target IP address> [-Source <source IP address>]'
        Write-Output '                                  [-Count/-n <number of ARP requests>] [-Interval <interval between ARP requests>]'
        return
    }

    $code = '[DllImport("iphlpapi.dll")]public static extern int SendARP(UInt32 DestIP,UInt32 SrcIP,byte[] pMacAddr,ref UInt32 PhyAddrLen);'
    $type = Add-Type -MemberDefinition $code -Name Win32SendARP -PassThru

    $Target = $Target.Trim()
    $Source = $Source.Trim()

    try {
        $DstIP = [UInt32][System.Net.IPAddress]::Parse($Target).Address
    }
    catch {
        Write-Error "Target IP address $Target is invalid. Please check it and try again."
        return
    }

    if ($Source) {
        try {
            $SrcIP = [UInt32][System.Net.IPAddress]::Parse($Source).Address
        }
        catch {
            Write-Error "Source IP address $Source is invalid. Please check it and try again."
            return
        }
    }
    else {
        $SrcIP = [UInt32]0
    }

    $MacAddr = New-Object Byte[] 6
    $n_sent = 0
    $n_received = 0
    $maxT = 0.
    $minT = 9999.
    $sumT = 0.

    Write-Output ''
    Write-Output "ARPING ${Target}:"
    for ($i = 1; $i -le $Count; $i++) {
        $n_sent++
        $MacAddr = New-Object Byte[] 6
        $result = $null
        $t = (Measure-Command { $result = $type::SendARP($DstIP, $SrcIP, $MacAddr, [ref][UInt32]$MacAddr.Length) }).TotalMilliseconds
        if ($result -eq 0) {
            # NO_ERROR
            $n_received++
            if ($t -gt $maxT) { $maxT = $t }
            if ($t -lt $minT) { $minT = $t }
            $sumT += $t        
            Write-Output "Reply from $(($MacAddr | %{ '{0:x2}' -F $_ }) -Join '-') (as $Target): index=$i, time=$(($t).ToString('0'))ms"
        }
        elseif ($result -eq 67) {
            # ERROR_BAD_NET_NAME
            Write-Output 'Request timed out.'
        }
        else {
            Write-Output "SendARP failed with error: $result"
        }
        if ($i -lt $Count) { Start-Sleep -Milliseconds ([Math]::Max(($Interval * 1000 - [Int]$t), 0)) }
    }
    Write-Output ''
    Write-Output "Ping statistics for $Target/arp:"
    Write-Output "    Packets: Sent=$n_sent, Received=$n_received, Lost=$($n_sent-$n_received) ($((($n_sent-$n_received)/$n_sent*100).ToString('0'))% loss)"
    if ($n_received -gt 0) {
        Write-Output 'Approximate round trip times in milli-seconds:'
        Write-Output "    Minimum = $(($minT).ToString('0'))ms, Maximum = $(($maxT).ToString('0'))ms, Average = $(($sumT/$n_received).ToString('0'))ms"
    }
}

Export-ModuleMember -Function 'Send-ARPRequest' -Alias 'arping'