CreateInternalEthernetPortDynamicMac method of the Msvm_VirtualSwitchManagementService class

Creates a new internal Ethernet port. It's almost the same as CreateInternalEthernetPort expect for the new internal Ethernet port's MAC address is created dynamically instead of being passed as a parameter.


uint32 CreateInternalEthernetPortDynamicMac(
  [in]  string                        Name,
  [in]  string                        FriendlyName,
  [out] Msvm_InternalEthernetPort REF CreatedInternalEthernetPort


Name [in]

Type: string

The name of the port. This name must be unique.

FriendlyName [in]

Type: string

A user-readable name for the port.

CreatedInternalEthernetPort [out]

Type: Msvm_InternalEthernetPort

Upon successful completion of this method, this parameter contains the created switch port. See Msvm_InternalEthernetPort.

Return value

Type: uint32

The method returns 0 if it succeeded synchronously. Any other return value indicates an error.

Completed with No Error (0)

Method Parameters Checked - Job Started (4096)

Failed (32768)

Access Denied (32769)

Not Supported (32770)

Status is unknown (32771)

Timeout (32772)

Invalid parameter (32773)

System is in used (32774)

Invalid state for this operation (32775)

Incorrect data type (32776)

System is not available (32777)

Out of memory (32778)


Access to the Msvm_VirtualSwitchManagementService class might be restricted by UAC Filtering. For more information, see User Account Control and WMI.


The following C# sample creates an internal Ethernet port with a dynamic MAC address. The referenced utilities can be found in Common Utilities for the Virtualization Samples.

using System;
using System.Management;

namespace HyperVSamples
    class CreateInternalEthernetPortDynamicMacClass
        static ManagementObject CreateInternalEthernetPortDynamicMac(string friendlyName, string name)
            ManagementScope scope = new ManagementScope(@"root\virtualization", null);
            ManagementObject switchService = Utility.GetServiceObject(scope, "Msvm_VirtualSwitchManagementService");

            ManagementObject createdInternalEthernetPort = null;

            ManagementBaseObject inParams = switchService.GetMethodParameters("CreateInternalEthernetPortDynamicMac");
            inParams["FriendlyName"] = friendlyName;
            inParams["Name"] = name;
            ManagementBaseObject outParams = switchService.InvokeMethod("CreateInternalEthernetPortDynamicMac", inParams, null);
            if ((UInt32)outParams["ReturnValue"] == ReturnCode.Completed)
                createdInternalEthernetPort = new ManagementObject(outParams["CreateInternalEthernetPortDynamicMac"].ToString());
                Console.WriteLine("{0} was created successfully", inParams["Name"]);
                Console.WriteLine("Failed to create {0} switch.", inParams["Name"]);
            return createdInternalEthernetPort;

        static void Main(string[] args)
            if (args != null && args.Length != 2)
                Console.WriteLine("Usage: CreateInternalEthernetPortDynamicMac FriendlyName Name");
                Console.WriteLine("Example: CreateInternalEthernetPort \"{0}\" {1}",
                    "First internal Ethernet Port",
            CreateInternalEthernetPortDynamicMac(args[0], args[1]);

The following VBScript sample creates an internal Ethernet port with a dynamic MAC address.

dim objWMIService
dim switchService
dim fileSystem

const wmiSuccessful = 0


' Main
Sub Main()
    set fileSystem = Wscript.CreateObject("Scripting.FileSystemObject")
    strComputer = "."

    set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\virtualization")
    set createdInternalEthernetPort = CreateInternalEthernetPortDynamicMac
    if Not (createdInternalEthernetPort Is Nothing) then
        WriteLog "Done"
        WriteLog Format1("Err.Number: {0}", Err.Number)
        WriteLog Format1("Err.Description:{0}",Err.Description)
    end if
End Sub

' Retrieve GetVirtualSwitchManagementServiceInstance from WMI
Sub GetVirtualSwitchManagementServiceInstance()

    query = "select * from Msvm_VirtualSwitchManagementService"
    set managementServiceCol= objWMIService.ExecQuery(query)
    For Each instance in managementServiceCol
        set switchService = instance

End Sub

' Create a virtual switch by calling CreateSwitch WMI method
Function CreateInternalEthernetPortDynamicMac()
    set CreateInternalEthernetPortDynamicMac = Nothing
    set objInParam = switchService.Methods_("CreateInternalEthernetPortDynamicMac").InParameters.SpawnInstance_()
    objInParam.FriendlyName = "First Internal Ethernet Dynamic Mac Port"
    objInParam.Name = "FirstInternalDynamicMacPort"

    set objOutParams = switchService.ExecMethod_("CreateInternalEthernetPortDynamicMac", objInParam)

    if objOutParams.ReturnValue = wmiSuccessful then
        set CreateInternalEthernetPortDynamicMac = objWMIService.Get(objOutParams.CreatedInternalEthernetPort)
        WriteLog Format1("CreateInternalEthernetPort failed with error code {0}", objOutParams.ReturnValue)
    end if

End Function

' Create the console log files.
Sub WriteLog(line)
    dim fileStream
    set fileStream = fileSystem.OpenTextFile(".\CreateSwitchPort.log", 8, true)
    WScript.Echo line
    fileStream.WriteLine line

End Sub

' The string formatting functions to avoid string concatenation.
Function Format1(myString, arg0)
    Format1 = Replace(myString, "{0}", arg0)
End Function


Minimum supported client
None supported
Minimum supported server
Windows Server 2008
End of client support
None supported
End of server support
Windows Server 2012

See also