Public/Invoke-ALHWakeOnLan.ps1

<#PSScriptInfo
 
.VERSION 1.1.0
 
.GUID 5cbd7525-1d02-41ab-93f3-b78f276a4cf6
 
.AUTHOR Dieter Koch
 
.COMPANYNAME
 
.COPYRIGHT (c) 2021-2023 Dieter Koch
 
.TAGS
 
.LICENSEURI https://github.com/admins-little-helper/ALH/blob/main/LICENSE
 
.PROJECTURI https://github.com/admins-little-helper/ALH
 
.ICONURI
 
.EXTERNALMODULEDEPENDENCIES
 
.REQUIREDSCRIPTS
 
.EXTERNALSCRIPTDEPENDENCIES
 
.RELEASENOTES
    1.0.0
    Initial release
 
    1.0.1
    Fixed issue with WolProxy in case a hostname is specified instead of an ip address.
    Changed behaviour to disallow -Wait parameter together with -WolProxy parameter as it makes no sense to have this together.
 
    1.0.2
    Fixed count of attempts
 
    1.0.3
    Fixed issue when multiple MAC addresses are given by parameter.
 
    1.1.0
    Added paramter 'UseWolUdpPort7' to support magic packets with UDP port 7 and UDP port 9 (default).
 
#>



<#
 
.DESCRIPTION
 Function to send wake on lan magic packet.
 
 Basic idea about how to send a magic packet based on:
 https://www.pdq.com/blog/wake-on-lan-wol-magic-packet-powershell/
 
#>



function Invoke-ALHWakeOnLan {
    <#
    .SYNOPSIS
        Function to send wake on lan magic packet.
 
    .DESCRIPTION
        This function sends a magic packet (WoL / Wake-On-Lan) to wake up one ore multiple systems specified
        by their MAC address.
 
    .PARAMETER MacAddress
        String. One or more strings specifying the target MAC address to wake up.
 
    .PARAMETER WolProxy
        String. IP address or hostname of a system that acts as Wake-On-Lan proxy and forwards the
        magic packet. Used in scenarios where you want to wake a host in a different subnet.
        Can not be combined with parameter Wait.
 
    .PARAMETER Wait
        Switch. If specified, the function checks if the system comes up and waits for about 40 seconds per system.
        Can not be combined with parameter WolProxy.
 
    .EXAMPLE
        Invoke-ALHWakeOnLan -MacAddress "00:11:22:33:44:55"
 
        Send magic packet to wake up host with MAC address '00:11:22:33:44:55'
 
    .EXAMPLE
        Invoke-ALHWakeOnLan -MacAddress "00:11:22:33:44:55" -Wait -Verbose
 
        Send magic packet to wake up host with MAC address '00:11:22:33:44:55' and wait until it is up or timeout is reached.
 
    .EXAMPLE
        Invoke-ALHWakeOnLan -MacAddress "00:11:22:33:44:55" -WolProxy 10.255.255.255
 
        Send magic packet to wake up host with MAC address '00:11:22:33:44:55' and use WolProxy 10.255.255.255.
 
    .EXAMPLE
        Invoke-ALHWakeOnLan -MacAddress '00:11:22:33:44:55', '66:77:88:99:AA:BB'
 
        Send magic packet to wake up hosts with MAC address '00:11:22:33:44:55' and '66:77:88:99:AA:BB'
 
    .EXAMPLE
        Invoke-ALHWakeOnLan -MacAddress '00:11:22:33:44:55', '66:77:88:99:AA:BB' -UseWolPort7
 
        Send magic packet to wake up hosts with MAC address '00:11:22:33:44:55' and '66:77:88:99:AA:BB' using UDP port 7 instead of port 9.
 
    .INPUTS
        System.String
 
    .OUTPUTS
        Nothing
 
    .NOTES
        Author: Dieter Koch
        Email: diko@admins-little-helper.de
 
    .LINK
        https://github.com/admins-little-helper/ALH/blob/main/Help/Invoke-ALHWakeOnLan.txt
    #>


    [CmdletBinding(DefaultParameterSetName = "default")]
    param (
        [Parameter(Mandatory, ValueFromPipeline)]
        [string[]]
        $MacAddress,

        [Parameter(ParameterSetName = "WolProxy")]
        [ValidateNotNullOrEmpty()]
        [string]
        $WolProxy,

        [Parameter(ParameterSetName = "NoWolProxy")]
        [switch]
        $Wait,

        [switch]
        $UseWolUdpPort7
    )

    begin {
        if ([string]::IsNullOrEmpty($WolProxy)) {
            $WolProxyTargetIP = [System.Net.IPAddress]::Broadcast
        }
        else {
            if ($WolProxy -as [System.Net.IPAddress]) {
                Write-Verbose -Message "Specified Wake-On-Lan proxy seems to be an IP address"
                $WolProxyTargetIP = ($WolProxy -as [System.Net.IPAddress]).IpAddressTostring
            }
            else {
                try {
                    Write-Verbose -Message "Trying to resolve the specified Wake-On-Lan proxy address in DNS"
                    $WolProxyTargetIP = ([System.Net.Dns]::GetHostByName($WolProxy)).AddressList[0].IPAddressToString
                }
                catch {
                    Write-Warning -Message "Wake-On-Lan proxy hostname '$WolProxy' could not be resolved to an IP address."
                    break
                }
            }
        }

        if ([string]::IsNullOrEmpty($WolProxyTargetIP)) {
            Write-Error -Message "Unable to correctly define target address for Wake-On-Lan. Aborting."
            break
        }

        # Set the UDP port to be used. Default is UDP port 9. Port 7 can also be used accoridng to the standard.
        # https://en.wikipedia.org/wiki/Wake-on-LAN
        if ($UseWolUdpPort7.IsPresent) {
            $WolUdpPort = 7
        }
        else {
            $WolUdpPort = 9
        }
    }

    process {
        foreach ($Target in $MacAddress) {
            Write-Information -MessageData "Trying to wake up system with MAC address: '$Target'..." -InformationAction Continue
            $MacByteArray = $Target -split "[:-]" | ForEach-Object { [Byte] "0x$_" }
            [Byte[]] $MagicPacket = (, 0xFF * 6) + ($MacByteArray * 16)

            $UdpClient = New-Object System.Net.Sockets.UdpClient

            Write-Verbose -Message "Sending magic packet to address '$WolProxyTargetIP'"
            $UdpClient.Connect($WolProxyTargetIP, $WolUdpPort)
            $null = $UdpClient.Send($MagicPacket, $MagicPacket.Length)
            $UdpClient.Close()

            if ($Wait.IsPresent) {
                $MaxAttempts = 20
                Write-Information -MessageData "Checking if host with MAC address '$Target' comes up..." -InformationAction Continue

                for ($i = 1; $i -lt $MaxAttempts; $i++) {
                    Write-Verbose -Message "Attempt #$i of $MaxAttempts"

                    $ArpRecord = Get-NetNeighbor -LinkLayerAddress $Target -ErrorAction SilentlyContinue
                    if ($null -ne $ArpRecord) {
                        Write-Verbose -Message "Found record in ARP table for MAC address '$Target' with IP address '$($ArpRecord.IPAddress)'"
                        Write-Verbose -Message "Trying to resolve ip to hostname"
                        $DnsRecord = [System.Net.Dns]::GetHostByAddress($ArpRecord.IPAddress)

                        if ($null -ne $DnsRecord) {
                            Write-Information -MessageData "DNS record found for IP '$($ArpRecord.IPAddress)' --> '$($DnsRecord.HostName)'" -InformationAction Continue
                        }
                        else {
                            Write-Warning -Message "No DNS record found for IP '$($ArpRecord.IPAddress)'"
                        }

                        if (Test-Connection -TargetName $ArpRecord.IPAddress -Ping -Count 1 -Quiet) {
                            Write-Information -MessageData "Host repsonds to ping on IP address '$($ArpRecord.IPAddress)'" -InformationAction Continue
                        }
                        else {
                            Write-Warning -Message "Host does NOT (yet) respond to ping on IP address '$($ArpRecord.IPAddress)'"
                        }

                        break
                    }
                    else {
                        Write-Verbose -Message "No ARP record found. Waiting 2 seconds before retrying"

                        if ($i -eq $MaxAttempts -or $i -eq $($MaxAttempts - 1)) {
                            Write-Warning -Message "Reached maximum number of attempts. No success so far. Giving up."
                        }
                    }

                    Start-Sleep -Seconds 2
                }
            }
        }
    }
}

#region EndOfScript
<#
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#
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# | ____| | | / _| / ____| (_) | |
# | |__ _ __ __| | ___ | |_ | (___ ___ _ __ _ _ __ | |_
# | __| | '_ \ / _` | / _ \| _| \___ \ / __| '__| | '_ \| __|
# | |____| | | | (_| | | (_) | | ____) | (__| | | | |_) | |_
# |______|_| |_|\__,_| \___/|_| |_____/ \___|_| |_| .__/ \__|
# | |
# |_|
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# created with help of http://patorjk.com/software/taag/
#>

#endregion