SocketException

Represents an error that occurred when performing a synchronous or asynchronous socket operation.

Remarks

The SocketException class provides specific error codes and messages that are returned by the operating system's socket APIs. When a socket operation fails, a SocketException is thrown, and you can examine its ErrorCode property to determine the specific cause of the error.

The error codes are typically the same as the Winsock error codes (WSA*) on Windows and the POSIX error codes on Unix-like systems.

Commonly Encountered Error Codes

Here are some of the most frequent error codes you might encounter:

Example

The following example demonstrates how to catch a SocketException and display its error code and message.

// Example of catching SocketException
try
{
    // Attempt a socket operation that might fail, e.g., connecting to a closed port
    using (Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp))
    {
        IPEndPoint remoteEP = new IPEndPoint(IPAddress.Loopback, 12345); // Assuming port 12345 is not open
        socket.Connect(remoteEP);
    }
}
catch (SocketException ex)
{
    // Output the error code and message
    Console.WriteLine($"SocketException caught: ErrorCode = {ex.ErrorCode}, Message = {ex.Message}");
    // You can then map the error code to a known symbolic name or take specific actions
}
catch (Exception ex)
{
    // Handle other potential exceptions
    Console.WriteLine($"An unexpected exception occurred: {ex.Message}");
}

See Also

• IPAddress
• IPEndPoint
• Socket
• Exception