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MulticastOption Class

Contains IPAddress values used for joining and dropping multicast groups.

For a list of all members of this type, see MulticastOption Members.

System.Object
   System.Net.Sockets.MulticastOption

[Visual Basic]
Public Class MulticastOption
[C#]
public class MulticastOption
[C++]
public __gc class MulticastOption
[JScript]
public class MulticastOption

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Remarks

Use a MulticastOption to store the IPAddress of a multicast group you want to join or drop. Use the Socket.SetSocketOption method with the following parameters to join a multicast group.

Parameter Value
socketOptionLevel SocketOptionLevel.Udp
socketOptionName AddMembership
object MulticastOption

Use DropMembership to drop a multicast group.

Example

[Visual Basic, C#, C++] The following examples join the default IP interface to an IP multicast group. They assume the IP multicast group address in the range 224.0.0.0 to 239.255.255.255.

[Visual Basic] 
' This is the listener example that shows how to use the MulticastOption class. 
' In particular, it shows how to use the MulticastOption(IPAddress, IPAddress) 
' constructor, which you need to use if you have a host with more than one 
' network card.
' The first parameter specifies the multicast group address, and the second 
' specifies the local address of the network card you want to use for the data
' exchange.
' You must run this program in conjunction with the sender program as 
' follows:
' Open a console window and run the listener from the command line. 
' In another console window run the sender. In both cases you must specify 
' the local IPAddress to use. To obtain this address run the ipconfig comand 
' from the command line. 


Imports System
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports Microsoft.VisualBasic


Namespace Mssc.TransportProtocols.Utilities

  Module M_TestMulticastOption

    Public Class TestMulticastOption

      Private Shared mcastAddress As IPAddress
      Private Shared mcastPort As Integer
      Private Shared mcastSocket As Socket
      Private Shared mcastOption As MulticastOption


      Private Shared Sub MulticastOptionProperties()
        Console.WriteLine(("Current multicast group is: " + mcastOption.Group.ToString()))
        Console.WriteLine(("Current multicast local address is: " + mcastOption.LocalAddress.ToString()))
      End Sub 'MulticastOptionProperties


      Private Shared Sub StartMulticast()

        Try
          mcastSocket = New Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp)

          Console.Write("Enter the local IP address: ")

          Dim localIPAddr As IPAddress = IPAddress.Parse(Console.ReadLine())

          'IPAddress localIP = IPAddress.Any;
          Dim localEP As EndPoint = CType(New IPEndPoint(localIPAddr, mcastPort), EndPoint)

          mcastSocket.Bind(localEP)

          ' Define a MulticastOption object specifying the multicast group 
          ' address and the local IPAddress.
          ' The multicast group address is the same as the address used by the server.
          mcastOption = New MulticastOption(mcastAddress, localIPAddr)

          mcastSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership, mcastOption)

        Catch e As Exception
          Console.WriteLine(e.ToString())
        End Try
      End Sub 'StartMulticast


      Private Shared Sub ReceiveBroadcastMessages()
        Dim done As Boolean = False
        Dim bytes() As Byte = New [Byte](99) {}
        Dim groupEP As New IPEndPoint(mcastAddress, mcastPort)
        Dim remoteEP As EndPoint = CType(New IPEndPoint(IPAddress.Any, 0), EndPoint)


        Try
          While Not done
            Console.WriteLine("Waiting for multicast packets.......")
            Console.WriteLine("Enter ^C to terminate.")

            mcastSocket.ReceiveFrom(bytes, remoteEP)

            Console.WriteLine("Received broadcast from {0} :" + ControlChars.Lf + " {1}" + ControlChars.Lf, groupEP.ToString(), Encoding.ASCII.GetString(bytes, 0, bytes.Length))
          End While



          mcastSocket.Close()

        Catch e As Exception
          Console.WriteLine(e.ToString())
        End Try
      End Sub 'ReceiveBrodcastMessages


      Public Shared Sub Main(ByVal args() As String)
        ' Initialize the multicast address group and multicast port.
        ' Both address and port are selected from the allowed sets as
        ' defined in the related RFC documents. These are the same
        ' as the values used by the sender.
        mcastAddress = IPAddress.Parse("224.168.100.2")
        mcastPort = 11000

        ' Start a multicast group.
        StartMulticast()

        ' Display MulticastOption properties.
        MulticastOptionProperties()

        ' Receive broadcast messages.
        ReceiveBroadcastMessages()
      End Sub 'Main
    End Class 'TestMulticastOption

  End Module

End Namespace

[C#] 

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;


// This is the listener example that shows how to use the MulticastOption class. 
// In particular, it shows how to use the MulticastOption(IPAddress, IPAddress) 
// constructor, which you need to use if you have a host with more than one 
// network card.
// The first parameter specifies the multicast group address, and the second 
// specifies the local address of the network card you want to use for the data
// exchange.
// You must run this program in conjunction with the sender program as 
// follows:
// Open a console window and run the listener from the command line. 
// In another console window run the sender. In both cases you must specify 
// the local IPAddress to use. To obtain this address run the ipconfig comand 
// from the command line. 
//  
namespace Mssc.TransportProtocols.Utilities
{

  public class TestMulticastOption 
  {

    private static IPAddress mcastAddress;
    private static int mcastPort;
    private static Socket mcastSocket;
    private static MulticastOption mcastOption;


    private static void MulticastOptionProperties()
    {
      Console.WriteLine("Current multicast group is: " + mcastOption.Group);
      Console.WriteLine("Current multicast local address is: " + mcastOption.LocalAddress);
    }


    private static void StartMulticast() 
    {
    
      try 
      {
        mcastSocket = new Socket(AddressFamily.InterNetwork,
                                 SocketType.Dgram, 
                                 ProtocolType.Udp);
        
        Console.Write("Enter the local IP address: ");

        IPAddress localIPAddr = IPAddress.Parse(Console.ReadLine());
      
        //IPAddress localIP = IPAddress.Any;
        EndPoint localEP = (EndPoint)new IPEndPoint(localIPAddr, mcastPort);

        mcastSocket.Bind(localEP);

 
        // Define a MulticastOption object specifying the multicast group 
        // address and the local IPAddress.
        // The multicast group address is the same as the address used by the server.
        mcastOption = new MulticastOption(mcastAddress, localIPAddr);

        mcastSocket.SetSocketOption(SocketOptionLevel.IP, 
                                    SocketOptionName.AddMembership, 
                                    mcastOption);
    
      } 

      catch (Exception e) 
      {
        Console.WriteLine(e.ToString());
      }
    }

    private static void ReceiveBroadcastMessages() 
    {
      bool done = false;
      byte[] bytes = new Byte[100];
      IPEndPoint groupEP = new IPEndPoint(mcastAddress, mcastPort);
      EndPoint remoteEP = (EndPoint) new IPEndPoint(IPAddress.Any,0);
        
     
      try 
      {      
        while (!done) 
        {
          Console.WriteLine("Waiting for multicast packets.......");
          Console.WriteLine("Enter ^C to terminate.");

          mcastSocket.ReceiveFrom(bytes, ref remoteEP);

          Console.WriteLine("Received broadcast from {0} :\n {1}\n",
            groupEP.ToString(),
            Encoding.ASCII.GetString(bytes,0,bytes.Length));
          
          
        }

        mcastSocket.Close();
      } 

      catch (Exception e) 
      {
        Console.WriteLine(e.ToString());
      }
    }

    public static void Main(String[] args) 
    {
      // Initialize the multicast address group and multicast port.
      // Both address and port are selected from the allowed sets as
      // defined in the related RFC documents. These are the same 
      // as the values used by the sender.
      mcastAddress = IPAddress.Parse("224.168.100.2");
      mcastPort = 11000;
    
      // Start a multicast group.
      StartMulticast();
      
      // Display MulticastOption properties.
      MulticastOptionProperties();
      
      // Receive broadcast messages.
      ReceiveBroadcastMessages();
    }
  }
}

[C++] 

#using <mscorlib.dll>
#using <System.dll>

using namespace System;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Text;


// This program shows how to use the MultiCastOption type. In particular,
// it shows how to use the MultiCastOption(IPAddress, IPAddress) constructor,
// You need to use this constructor, in the case of multihomed host (i.e.,
// a host with more than one network card). With the first parameter you
// specify the multicast group address, with the second you specify the
// local address of one of the network cards you want to use for the data
// exchange.
// You must run this program in conjunction with the sender program as
// follows:
// Open a console window and run the listener from the command line.
// In another console window run the sender. In both cases you must specify
// the local IPAddress to use. To obtain this address run the ipconfig from
// the command line.
//

public __gc class TestMulticastOption {
private:
   static IPAddress*  mcastAddress;
   static int  mcastPort;
   static Socket*  mcastSocket;
   static MulticastOption*  mcastOption;

   static void MulticastOptionProperties() {
      Console::WriteLine(S"Current multicast group is: {0}", mcastOption->Group);
      Console::WriteLine(S"Current multicast local address is: {0}", mcastOption->LocalAddress);
   }

   static void StartMulticast() {

      try {
         mcastSocket = new Socket(AddressFamily::InterNetwork,
            SocketType::Dgram,
            ProtocolType::Udp);

         Console::Write(S"Enter the local IP Address: ");

         IPAddress* localIPAddr = IPAddress::Parse(Console::ReadLine());

         //IPAddress localIP = IPAddress::Any;
         EndPoint* localEP = dynamic_cast<EndPoint*>(new IPEndPoint(localIPAddr, mcastPort));

         mcastSocket->Bind(localEP);


         // Define a MuticastOption object specifying the multicast group
         // address and the local IPAddress.
         // The multicast group address is the same one used by the server.
         mcastOption = new MulticastOption(mcastAddress, localIPAddr);

         mcastSocket->SetSocketOption(SocketOptionLevel::IP,
            SocketOptionName::AddMembership,
            mcastOption);

      } catch (Exception* e) {
         Console::WriteLine(e);
      }
   }

   static void ReceiveBrodcastMessages() {
      bool done = false;
      Byte bytes[] = new Byte[100];
      IPEndPoint* groupEP = new IPEndPoint(mcastAddress, mcastPort);
      EndPoint* remoteEP = dynamic_cast<EndPoint*> (new IPEndPoint(IPAddress::Any, 0));

      try {
         while (!done) {
            Console::WriteLine(S"Waiting for Multicast packets.......");
            Console::WriteLine(S"Enter ^C to terminate.");

            mcastSocket->ReceiveFrom(bytes, &remoteEP);

            Console::WriteLine(S"Received broadcast from {0} :\n {1}\n",
               groupEP,
               Encoding::ASCII->GetString(bytes, 0, bytes->Length));
         }
         mcastSocket->Close();
      } catch (Exception* e) {
         Console::WriteLine(e);
      }
   }

public:
   static void Main() {
      // Initialize multicast address group and multicast port.
      // Both address and port are selected from the allowed sets as
      // defined in the related RFC documents. These are the same values
      // used by the sender.
      mcastAddress = IPAddress::Parse(S"224.168.100.2");
      mcastPort = 11000;

      // Start a multicast group.
      StartMulticast();

      // Display multicast option properties.
      MulticastOptionProperties();

      // Receive brodcast messages.
      ReceiveBrodcastMessages();
   }
};

int main()
{
   TestMulticastOption::Main();
}

[Visual Basic] 
' This sender example must be used in conjunction with the listener program.
' You must run this program as follows:
' Open a console window and run the listener from the command line. 
' In another console window run the sender. In both cases you must specify 
' the local IPAddress to use. To obtain this address, run the ipconfig command
' from the command line. 
'  
Imports System
Imports System.Net.Sockets
Imports System.Net
Imports System.Text
Imports Microsoft.VisualBasic

Namespace Mssc.TransportProtocols.Utilities

  Module M_TestMulticastOption

    Class TestMulticastOption

      Private Shared mcastAddress As IPAddress
      Private Shared mcastPort As Integer
      Private Shared mcastSocket As Socket


      Shared Sub JoinMulticastGroup()
        Try
          ' Create a multicast socket.
          mcastSocket = New Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp)

          ' Get the local IP address used by the listener and the sender to
          ' exchange multicast messages. 
          Console.Write(ControlChars.Lf + "Enter local IPAddress for sending multicast packets: ")
          Dim localIPAddr As IPAddress = IPAddress.Parse(Console.ReadLine())

          ' Create an IPEndPoint object. 
          Dim IPlocal As New IPEndPoint(localIPAddr, 0)

          ' Bind this endpoint to the multicast socket.
          mcastSocket.Bind(IPlocal)

          ' Define a MulticastOption object specifying the multicast group 
          ' address and the local IP address.
          ' The multicast group address is the same as the address used by the listener.
          Dim mcastOption As MulticastOption
          mcastOption = New MulticastOption(mcastAddress, localIPAddr)

          mcastSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership, mcastOption)

        Catch e As Exception
          Console.WriteLine((ControlChars.Lf + e.ToString()))
        End Try
      End Sub 'JoinMulticast


      Shared Sub BroadcastMessage(ByVal message As String)
        Dim endPoint As IPEndPoint

        Try
          'Send multicast packets to the listener.
          endPoint = New IPEndPoint(mcastAddress, mcastPort)
          mcastSocket.SendTo(ASCIIEncoding.ASCII.GetBytes(message), endPoint)
          Console.WriteLine("Multicast data sent.....")
        Catch e As Exception
          Console.WriteLine((ControlChars.Lf + e.ToString()))
        End Try

        mcastSocket.Close()
      End Sub 'BrodcastMessage


      Public Shared Sub Main(ByVal args() As String)
        ' Initialize the multicast address group and multicast port.
        ' Both address and port are selected from the allowed sets as
        ' defined in the related RFC documents. These are the same as the 
        ' values used by the sender.
        mcastAddress = IPAddress.Parse("224.168.100.2")
        mcastPort = 11000

        ' Join the listener multicast group.
        JoinMulticastGroup()

        ' Broadcast the message to the listener.
        BroadcastMessage("Hello multicast listener.")
      End Sub 'Main
    End Class 'TestMulticastOption

  End Module

End Namespace

[C#] 

using System;
using System.Net.Sockets;
using System.Net;
using System.Text;

// This sender example must be used in conjunction with the listener program.
// You must run this program as follows:
// Open a console window and run the listener from the command line. 
// In another console window run the sender. In both cases you must specify 
// the local IPAddress to use. To obtain this address,  run the ipconfig command 
// from the command line. 
//  
namespace Mssc.TransportProtocols.Utilities
{
  class TestMulticastOption
  {

    static IPAddress mcastAddress;
    static int mcastPort;
    static Socket mcastSocket;
   
    static void JoinMulticastGroup()
    {
      try
      {
        // Create a multicast socket.
        mcastSocket = new Socket(AddressFamily.InterNetwork, 
                                 SocketType.Dgram, 
                                 ProtocolType.Udp);
              
        // Get the local IP address used by the listener and the sender to
        // exchange multicast messages. 
        Console.Write("\nEnter local IPAddress for sending multicast packets: ");
        IPAddress  localIPAddr = IPAddress.Parse(Console.ReadLine());

        // Create an IPEndPoint object. 
        IPEndPoint IPlocal = new IPEndPoint(localIPAddr, 0);
        
        // Bind this endpoint to the multicast socket.
        mcastSocket.Bind(IPlocal);

        // Define a MulticastOption object specifying the multicast group 
        // address and the local IP address.
        // The multicast group address is the same as the address used by the listener.
        MulticastOption mcastOption;
        mcastOption = new MulticastOption(mcastAddress, localIPAddr);
        
        mcastSocket.SetSocketOption(SocketOptionLevel.IP, 
                                    SocketOptionName.AddMembership, 
                                    mcastOption);
     
      }
      catch (Exception e)
      {
        Console.WriteLine("\n" + e.ToString());
      }
    }

    static void BroadcastMessage(string message)
    {
      IPEndPoint endPoint;

      try
      {
        //Send multicast packets to the listener.
        endPoint = new IPEndPoint(mcastAddress,mcastPort);
        mcastSocket.SendTo(ASCIIEncoding.ASCII.GetBytes(message), endPoint);            
        Console.WriteLine("Multicast data sent.....");
      }
      catch (Exception e)
      {
        Console.WriteLine("\n" + e.ToString());
      }

      mcastSocket.Close();
    }
   
    
    static void Main(string[] args)
    {
      // Initialize the multicast address group and multicast port.
      // Both address and port are selected from the allowed sets as
      // defined in the related RFC documents. These are the same 
      // as the values used by the sender.
      mcastAddress = IPAddress.Parse("224.168.100.2");
      mcastPort = 11000;

      // Join the listener multicast group.
      JoinMulticastGroup();

      // Broadcast the message to the listener.
      BroadcastMessage("Hello multicast listener.");
    }
  }
}

[C++] 

#using <mscorlib.dll>
#using <System.dll>

using namespace System;
using namespace System::Net::Sockets;
using namespace System::Net;
using namespace System::Text;

// This is an auxiliary program to be used in conjunction with a listener
// program.
// You must run this program as follows:
// Open a console window and run the listener from the command line.
// In another console window run the sender. In both cases you must specify
// the local IPAddress to use. To obtain this address run the ipconfig
// from the command line.
//

__gc class TestMulticastOption {

   static IPAddress* mcastAddress;
   static int mcastPort;
   static Socket* mcastSocket;

   static void JoinMulticast() {
      try {
         // Create multicast socket.
         mcastSocket = new Socket(AddressFamily::InterNetwork,
            SocketType::Dgram,
            ProtocolType::Udp);

         // Get the local IP address used by the listener and the sender to
         // exchange data in a multicast fashion.
         Console::Write(S"\nEnter local IPAddress for sending multicast packets: ");
         IPAddress*  localIPAddr = IPAddress::Parse(Console::ReadLine());

         // Create an IPEndPoint Object*.
         IPEndPoint* IPlocal = new IPEndPoint(localIPAddr, 0);

         // Bind this end point to the multicast socket.
         mcastSocket->Bind(IPlocal);

         // Define a MuticastOption Object* specifying the multicast group
         // address and the local IPAddress.
         // The multicast group address is the same one used by the listener.
         MulticastOption* mcastOption;
         mcastOption = new MulticastOption(mcastAddress, localIPAddr);

         mcastSocket->SetSocketOption(SocketOptionLevel::IP,
            SocketOptionName::AddMembership,
            mcastOption);

      } catch (Exception* e) {
         Console::WriteLine(S"\n {0}", e);
      }
   }

   static void BrodcastMessage(String* message) {
      IPEndPoint* endPoint;

      try {
         //Send multicast packets to the listener.
         endPoint = new IPEndPoint(mcastAddress, mcastPort);
         mcastSocket->SendTo(ASCIIEncoding::ASCII->GetBytes(message), endPoint);
         Console::WriteLine(S"Multicast data sent.....");
      } catch (Exception* e) {
         Console::WriteLine(S"\n {0}", e);
      }

      mcastSocket->Close();
   }

public:
   static void main() {
      // Initialize multicast address group and multicast port.
      // Both address and port are selected from the allowed sets as
      // defined in the related RFC documents. These are the same values
      // used by the sender.
      mcastAddress = IPAddress::Parse(S"224.168.100.2");
      mcastPort = 11000;

      // Join the listener multicast group.
      JoinMulticast();

      // Broadcast message to the listener.
      BrodcastMessage(S"Hello multicast listener.");
   }
};

int main()
{
   TestMulticastOption::main();
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Namespace: System.Net.Sockets

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

Assembly: System (in System.dll)

See Also

MulticastOption Members | System.Net.Sockets Namespace

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