SQL Connection with public IP, named instance and port number

Question

I have had difficulty creating a connection string in c# that will connect to a remote SQL server using a public IP, named instance and a port number (other than 1433). Anyo

Answer 1

Using the servername tcp:,, as documented in SqlConnection.ConnectionString:

The name or network address of the instance of SQL Server to which to connect. The port number can be specified after the server name:

server=tcp:servername, portnumber

When specifying a local instance, always use (local). To force a protocol, add one of the following prefixes:

np:(local), tcp:(local), lpc:(local)

Data Source must use the TCP format or the Named Pipes format.

TCP format is as follows:

• tcp:\
• tcp:,

If you use the tcp:\ the SQL Browser service connection is required (port 1433) therefore is better to use the later format, with explicit port name:

Data Source=tcp:1.2.3.4,1234;User Id=...; Password=...