What is the default network protocol in SqlConnection class

Question

In following code snippet, What will be the network protocol used to connect to the SQL Server? TCP/IP or Named Pipes or others?

using System;
using System.Data.SqlClient;

class Program
{
    static void Main()
    {
    //
    // First access the connection string.
    // ... This may be autogenerated in Visual Studio.
    //
    string connectionString = "Server=SERVER\\INSTANCE;Database=myDataBase;User Id=myUsername;
Password=myPassword;"
    //
    // In a using statement, acquire the SqlConnection as a resource.
    //
    using (SqlConnection con = new SqlConnection(connectionString))
    {
        //
        // Open the SqlConnection.
        //
        con.Open();
        //
        // The following code uses an SqlCommand based on the SqlConnection.
        //
        using (SqlCommand command = new SqlCommand("SELECT TOP 2 * FROM Dogs1", con))
        using (SqlDataReader reader = command.ExecuteReader())
        {
        while (reader.Read())
        {
            Console.WriteLine("{0} {1} {2}",
            reader.GetInt32(0), reader.GetString(1), reader.GetString(2));
        }
        }
    }
    }
}

Answer 1

According to the SQL Server Native Client Configuration:

Protocols are tried in the order listed, attempting to connect using the top protocol first, and then the second listed protocol, etc.

BUT, we also read:

These settings are not used by Microsoft .NET SqlClient. The protocol order for .NET SqlClient is first TCP, and then named pipes, which cannot be changed.

So that is the order that they'll be attempted - TCP first, then Named Pipes - and so there's not "a" protocol that will be used - it depends on what succeeds.