.NET Documentation

SocketOptionName Enum

Specifies socket options.

Namespace: System.Net.Sockets
Assembly: System.Net.Primitives (in System.Net.Primitives.dll)

Syntax

public enum SocketOptionName

Members

Name	Description
AcceptConnection	Enables or disables the ability to accept connections on a listening socket. This option is used with SocketOptionLevel.Socket.
AddMembership	Adds a socket to a multicast group. This option is used with SocketOptionLevel.IP.
Broadcast	Enables or disables broadcast packets. This option is used with SocketOptionLevel.Socket.
BugWorkaround	Enables or disables a bug workaround. This option is used with SocketOptionLevel.Socket.
DontFragment	Prevents fragmentation of outgoing UDP packets. This option is used with SocketOptionLevel.IP.
DropMembership	Removes a socket from a multicast group. This option is used with SocketOptionLevel.IP.
ExclusiveAddressUse	Enables or disables the exclusive use of an address. This option is used with SocketOptionLevel.Socket.
FragmentSize	Specifies the fragmentation size for outgoing packets. This option is used with SocketOptionLevel.IP.
HopLimit	Specifies the hop limit for outgoing IP packets. This option is used with SocketOptionLevel.IP.
IPOptions	Enables or disables the use of IP options. This option is used with SocketOptionLevel.IP.
KeepAlive	Enables or disables the keep-alive socket option. This option is used with SocketOptionLevel.Socket.
Linger	Specifies the time-out value for linger operations. This option is used with SocketOptionLevel.Socket.
NoDelay	Enables or disables the Nagle algorithm. This option is used with SocketOptionLevel.Tcp.
OutBandInline	Enables or disables the inline transmission of out-of-band data. This option is used with SocketOptionLevel.Socket.
ProtocolInformation	Enables or disables the protocol information. This option is used with SocketOptionLevel.Socket.
ReceiveBuffer	Specifies the size of the receive buffer for the socket. This option is used with SocketOptionLevel.Socket.
ReceiveMessageTimeout	Specifies the time-out value for receiving messages. This option is used with SocketOptionLevel.Socket.
ReceiveTimeout	Specifies the time-out value for receiving data. This option is used with SocketOptionLevel.Socket.
ReuseAddress	Enables or disables the reuse of an address. This option is used with SocketOptionLevel.Socket.
SendBuffer	Specifies the size of the send buffer for the socket. This option is used with SocketOptionLevel.Socket.
SendMessageTimeout	Specifies the time-out value for sending messages. This option is used with SocketOptionLevel.Socket.
SendTimeout	Specifies the time-out value for sending data. This option is used with SocketOptionLevel.Socket.
TypeCompatibility	Enables or disables type compatibility. This option is used with SocketOptionLevel.Socket.
TypeToService	Specifies the type of service to be provided. This option is used with SocketOptionLevel.IP.
UseLoopback	Enables or disables the use of the loopback interface. This option is used with SocketOptionLevel.IP.
Vad	Enables or disables voice activity detection. This option is used with SocketOptionLevel.IP.

Remarks

The SocketOptionName enumeration provides constants for various socket options that can be set or retrieved using the Socket.SetSocketOption and Socket.GetSocketOption methods.

Each option is associated with a specific SocketOptionLevel, which indicates the protocol or layer to which the option applies (e.g., SocketOptionLevel.Socket for general socket options, SocketOptionLevel.Tcp for TCP-specific options, or SocketOptionLevel.IP for IP-specific options).

When setting or getting a socket option, you will typically use a combination of the appropriate SocketOptionLevel and a SocketOptionName value.

Example Usage

The following example demonstrates how to enable the KeepAlive option for a TCP socket:

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

public class SocketOptionExample
{
    public static void Main(string[] args)
    {
        Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

        try
        {
            // Enable KeepAlive
            byte[] keepAliveValues = new byte[] { 1, 0, 0, 0, Convert.ToByte(10), 0, 0, 0, Convert.ToByte(5), 0, 0, 0 }; // Keep-alive enabled, time=10s, interval=5s
            socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, true);
            // Note: For more detailed KeepAlive configuration (time, interval, retry count),
            // you would typically use Winsock's SIO_KEEPALIVE_VALS IOCTL, which is more complex in .NET.
            // The basic 'true' sets it to default OS values.

            Console.WriteLine("KeepAlive option enabled for the socket.");

            // Example: Get the ReceiveTimeout value
            int receiveTimeout = (int)socket.GetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout);
            Console.WriteLine($"Current ReceiveTimeout: {receiveTimeout} ms");

            // Set a new ReceiveTimeout
            socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, 30000); // 30 seconds
            receiveTimeout = (int)socket.GetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout);
            Console.WriteLine($"New ReceiveTimeout set to: {receiveTimeout} ms");

            // Example: Broadcast option (typically for UDP)
            // socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, true);
            // Console.WriteLine("Broadcast option enabled.");
        }
        catch (SocketException e)
        {
            Console.WriteLine($"SocketException caught: {e.Message}");
        }
        finally
        {
            if (socket.Connected)
            {
                socket.Disconnect(false);
            }
            socket.Close();
        }
    }
}