Error when trying to connect using port number in server name field: "error: 40 - Could not open (20768)

Trying to connect to SQL Server database using a port number in the server name field and it keeps giving the following error message:

"The following "Auto-Connections" failed:

An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error 40 - Could not open a connection to SQL Server)"

Port numbers are not accepted in server name field.

1) Use IP only in sever name field.
2) Type in a server name.
3) Use discovery service to select a server instead of typing in the name.