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SocketOptionLevel Enum

Represents the level at which a socket option is set or retrieved.

This enumeration is used with the Socket.SetSocketOption and Socket.GetSocketOption methods to specify the protocol level at which the option applies. Common levels include the socket level itself (Socket), the transport layer (Transport), and the internet layer (IP).

Members

Name Value Description
Socket 0 Specifies socket options.
Transport 1 Specifies transport layer options.
IP 2 Specifies Internet Protocol (IP) options.
IPv6 3 Specifies Internet Protocol version 6 (IPv6) options.
TCP 4 Specifies Transmission Control Protocol (TCP) options.
UDP 5 Specifies User Datagram Protocol (UDP) options.

Usage Example

This example demonstrates how to set the `NoDelay` option on a socket to disable the Nagle algorithm, which can improve performance for small, frequent transmissions.
C#
using System;
using System.Net;
using System.Net.Sockets;

public class SocketOptionExample
{
    public static void Main(string[] args)
    {
        // Create a TCP/IP socket.
        using (Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp))
        {
            try
            {
                // Connect to a remote endpoint.
                IPAddress ipAddress = IPAddress.Parse("127.0.0.1");
                int port = 13000;
                socket.Connect(new IPEndPoint(ipAddress, port));

                Console.WriteLine($"Connected to {socket.RemoteEndPoint}");

                // Disable the Nagle algorithm.
                // SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay, true);
                socket.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay, true);
                Console.WriteLine("Nagle algorithm disabled.");

                // You can now send/receive data...

                // Example: Get the current value of NoDelay option
                bool isNoDelayEnabled = (bool)socket.GetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay);
                Console.WriteLine($"NoDelay is currently: {isNoDelayEnabled}");

                // Disconnect from the remote endpoint.
                socket.Shutdown(SocketShutdown.Both);
                socket.Close();
                Console.WriteLine("Socket closed.");
            }
            catch (SocketException e)
            {
                Console.WriteLine($"SocketException: {e.Message}");
            }
            catch (ArgumentNullException e)
            {
                Console.WriteLine($"ArgumentNullException: {e.Message}");
            }
            catch (ArgumentException e)
            {
                Console.WriteLine($"ArgumentException: {e.Message}");
            }
            catch (Exception e)
            {
                Console.WriteLine($"Unexpected exception: {e.Message}");
            }
        }
    }
}

Remarks

The specific options available for each level vary depending on the operating system and the network protocols in use. Always refer to the documentation for SocketOptionName for a complete list of options associated with each SocketOptionLevel.

It is important to understand the implications of setting certain socket options, as they can affect network performance, security, and reliability.

See Also