Remotely manipulate RDP port assignments with PowerShell

Edit-RdpPort.ps1

Function Edit-RdpPort {
	<#
	.SYNOPSIS
	Changes the port assigned to RDP
	.DESCRIPTION
	Change the port assigned to RDP by updating the registry and restarting relevant services
	.PARAMETER ComputerName
	ComputerName that will have its port changed
	.PARAMETER Port
	New port number
	.EXAMPLE
	Edit-RDPPort -ComputerName 'Contoso1' -Port 7777
	#>
	Param(
		[String]$ComputerName = $env:ComputerName,
		[Int]$Port = 3389
	)
	If (-Not (Test-RdpPort -ComputerName $ComputerName -Port $Port)) {
		Write-Host -ForegroundColor Red "The new port is not reachable."
		Read-Host -Prompt "Press Enter to continue or Ctrl+C to quit"
	}
	Write-Host -NoNewline "Old port: "
	Get-RdpPort -ComputerName $ComputerName

	Set-RdpPort -ComputerName $ComputerName -Port $Port

	Write-Host -NoNewline "New port: "
	Get-RdpPort -ComputerName $ComputerName

	Restart-RdpServices -ComputerName $ComputerName
}

Function Test-RdpPort {
	<#
	.SYNOPSIS
	Tests the port assigned to RDP
	.DESCRIPTION
	Test the port assigned to RDP by attempting to connect
	.PARAMETER ComputerName
	ComputerName that will have port tested
	.PARAMETER Port
	TCP port to be tested
	.EXAMPLE
	Test-RDPPort -ComputerName 'Contoso1' -Port 7777
	#>
	Param(
		[String]$ComputerName = $env:ComputerName,
		[Int]$Port = (Get-RdpPort -ComputerName $ComputerName)
	)
	$ErrorActionPreference = "silentlycontinue"
	$Client = New-Object System.Net.Sockets.TcpClient
	$Client.Connect($ComputerName,$Port)
	Return $Client.Connected
}

Function Set-RdpPort {
	<#
	.SYNOPSIS
	Sets the port assigned to RDP
	.DESCRIPTION
	Set the port assigned to RDP by writing to the registry
	.PARAMETER ComputerName
	ComputerName that will have its port changed
	.PARAMETER Port
	New port number
	.EXAMPLE
	Set-RDPPort -ComputerName 'Contoso1' -Port 7777
	#>
	Param(
		[String]$ComputerName = $env:ComputerName,
		[Int]$Port = 3389
	)
	$Path = "Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp"
	Invoke-Command -ComputerName $ComputerName -ScriptBlock { Set-ItemProperty -Path $Args[0] -Name "PortNumber" -Value $Args[1] } -ArgumentList $Path,$Port
}

Function Get-RdpPort {
	<#
	.SYNOPSIS
	Gets the port assigned to RDP
	.DESCRIPTION
	Get the port assigned to RDP by looking in the registry
	.PARAMETER ComputerName
	ComputerName that will have its port checked
	.EXAMPLE
	Get-RDPPort -ComputerName 'Contoso1'
	#>
	Param([String]$ComputerName = $env:ComputerName)
	$Path = "Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp"
	$Config = Invoke-Command -ComputerName $ComputerName -ScriptBlock { Get-ItemProperty -Path $Args[0] } -ArgumentList $Path
	Return $Config.PortNumber
}

Function Restart-RdpServices {
	<#
	.SYNOPSIS
	Restarts services related to RDP
	.DESCRIPTION
	Restarts services related to RDP: 'TermService' and 'Remote Desktop Services UserMode Port Redirector' 
	.PARAMETER ComputerName
	ComputerName that will have RDP related services restarted.
	.EXAMPLE
	Restart-RDP -ComputerName 'Contoso1'
	#>
	Param([string]$ComputerName = $env:ComputerName)
	Get-Service -ComputerName $ComputerName -Name 'UmRdpService' | Stop-Service -Force
	Get-Service -ComputerName $ComputerName -Name 'TermService'  | Stop-Service -Force
	Get-Service -ComputerName $ComputerName -Name 'TermService'  | Start-Service
	Get-Service -ComputerName $ComputerName -Name 'UmRdpService' | Start-Service
	Return "Services restarted"
}

Edit-RdpPortLocal.ps1

Function Edit-RdpPort {
	<#
		.SYNOPSIS
			Changes the port assigned to RDP
		.DESCRIPTION
			Changes the port assigned to RDP by updating the registry and restarting relevant services
		.PARAMETER Port
			Specifies new port number. Defaults to 3389
		.EXAMPLE
			Edit-RdpPort -Port 7777
			Old port: 3389
			New port: 7777
		.EXAMPLE
			Edit-RdpPort 5656
			The new port is not reachable.
			Press Enter to continue or Ctrl+C to quit
	#>
	Param (
		[Int]$Port = 3389
	)
	Process {
		If (-Not (Test-RdpPort -Port $Port)) {
			Write-Host -ForegroundColor Red "The new port is not reachable."
			Read-Host -Prompt "Press Enter to continue or Ctrl+C to quit"
		}
		Write-Host "Old port: $(Get-RdpPort)"
		Test-RdpPort
		Set-RdpPort -Port $Port
		Write-Host "New port: $(Get-RdpPort)"
		Test-RdpPort
		Restart-RdpServices
	}
}


Function Test-RdpPort {
	<#
		.SYNOPSIS
			Tests the port assigned to RDP
		.DESCRIPTION
			Tests the port assigned to RDP by attempting to connect
		.PARAMETER Port
			Specifies TCP port to be tested. Defaults to current RDP port
		.EXAMPLE
			Test-RdpPort -Port 7777
	#>
	Param (
		[Int]$Port = (Get-RdpPort)
	)
	Process {
		$ErrorActionPreference = "SilentlyContinue"
		$Client = New-Object -TypeName System.Net.Sockets.TcpClient
		$Client.Connect("localhost", $Port)
		$Client.Connected
	}
}


Function Set-RdpPort {
	<#
		.SYNOPSIS
			Sets the port assigned to RDP
		.DESCRIPTION
			Set the port assigned to RDP by writing to the registry
		.PARAMETER Port
			Species new port number. Defaults to 3389
		.EXAMPLE
			Set-RdpPort -Port 7777
	#>
	Param (
		[Int]$Port = 3389
	)
	Process {
		$Path = "Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp"
		Set-ItemProperty -Path $Path -Name "PortNumber" -Value $Port
	}
}


Function Get-RdpPort {
	<#
		.SYNOPSIS
			Gets the port assigned to RDP
		.DESCRIPTION
			Get the port assigned to RDP by looking in the registry
	#>
	Process {
		$Path = "Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp"
		$Config = Get-ItemProperty -Path $Path
		$Config.PortNumber
	}
}


Function Restart-RdpServices {
	<#
		.SYNOPSIS
			Restarts services related to RDP
		.DESCRIPTION
			Restarts services related to RDP: 'TermService' and 'Remote Desktop Services UserMode Port Redirector'
	#>
	Process {
		Get-Service -Name "UmRdpService" | Stop-Service -Force
		Get-Service -Name "TermService"  | Stop-Service -Force
		Get-Service -Name "TermService"  | Start-Service
		Get-Service -Name "UmRdpService" | Start-Service
	}
}