You cannot connect to SQL Server on any port other than 1433 if you use a protocol other than TCP/IP

This article helps you resolve the problem that occurs when you use a protocol other than TCP/IP to connect to SQL Server on a port other than 1433.

Original product version:   Visual C#
Original KB number:   307645


When you use a protocol other than Transmission Control Protocol/Internet Protocol (TCP/IP), SqlConnection.Open fails if you specify a port number other than 1433 to connect to an instance of SQL Server.


To resolve this problem, use TCP/IP protocol, and include Server=ComputerName, PortNumber in the connection string.

Steps to reproduce the behavior

  1. Start Visual Studio .NET.

  2. Create a new Visual C# .NET Console Application project.

  3. Make sure that your project contains a reference to the System.Data namespace, and add a reference to this namespace if it does not.

  4. Use the using statement on the System, System.Data, System.Data.SqlClient namespaces so that you are not required to qualify declarations in those namespaces later in your code.

    using System;
    using System.Data;
    using System.Data.SqlClient;
  5. Visual Studio creates a static class and an empty Main procedure by default. Copy the following code, and paste it in the Code window:


    You must change the User ID <username> value and the password <strong password> value to the correct values before you run this code. Make sure that User ID has the appropriate permissions to perform this operation on the database.

    class Class1
        static void Main(string[] args)
            string sConnectionString;
            sConnectionString = "User ID=<username>;Password =<strong password>;Initial Catalog=pubs;Data Source=myServer,1200";
            SqlConnection objConn = new SqlConnection(sConnectionString);
            SqlDataAdapter daAuthors = new SqlDataAdapter("Select * From Authors", objConn);
            DataSet dsPubs = new DataSet("Pubs");
            daAuthors.FillSchema(dsPubs, SchemaType.Source, "Authors");
            daAuthors.Fill(dsPubs, "Authors");
            daAuthors.MissingSchemaAction = MissingSchemaAction.AddWithKey;
            daAuthors.Fill(dsPubs, "Authors");
            DataTable tblAuthors;
            tblAuthors = dsPubs.Tables["Authors"];
            foreach (DataRow drCurrent in tblAuthors.Rows)
                Console.WriteLine("{0} {1}",
  6. Modify the sConnectionString string as appropriate for your environment.

  7. Save your project.

  8. On the Debug menu, click Start, and run your project to connect to the database.