SQL Server - SQL Network Interfaces, error: 28 - Server doesn't support requested protocol

Asked By Hoggar on 21-Apr-08 01:06 PM
I installed MS SQL 2005 Server Express Edition instance X on SERVER where is
already installed SQL 2000. When I try to connect to SERVER\X from CLIENT
machine in LAN with SQL Server Management Studio Express I get error:
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: SQL Network Interfaces, error: 28 - Server doesn't support
requested protocol) (.Net SqlClient Data Provider)

From the SERVER I connect regulary with SQL Server Management Studio Express
to instance SERVER\X.
SQL Server Express is working, SQL browser is working. It is enabled remote
connections.

One more thing I can regulary connect from CLIENT with Enterprise Manager to
SERVER on SQL 2000.

How could I solve this problem?




RobKraf replied on 21-Apr-08 02:20 PM
You may need to use the SQL Server 2005 Surface Area Configuration to give
access to both Local and Remote connections.  By default, the express edition
allows only local connections.
ekre replied on 21-Apr-08 03:29 PM
I didn't understand if X (which is the new Express Edition instance I
guess?) is a new instance or old... You say "you installed it and tried to
connect but it didn't work" and you also say "from the SERVER (which is the
SQL Server server I believe?) you connect regularly using SSMSE to the X
instance (which was supposed to be the new one according to your first
statement??)"... Maybe I just didn't get it...

Anyway, if Windows Firewall is ON on the SQL Server server, then set a
static port for your problematic instance and let that port in Windows
Firewall. Ensure that TCP protocol is enabled as Rob's already mentioned.
Set your IP settings and port settings and try again.

--
Ekrem Önsoy
Hoggar replied on 21-Apr-08 07:56 PM
This was the problem, thank you very much!

But why in server properties (in SSMSE) is remote connections enabled?
ekre replied on 22-Apr-08 04:09 AM
Properties window is about executing Stored Procedures from remote servers.
If you check it (and enable Remote Connections from Surface Area...) then
your remote servers will be able to execute SPs against that instance of SQL
Server.

Whereas, Remote Connections in Surface Area Configuration is about
enabling\disabling TCP or Named Pipes protocols. You can enable\disabl these
protocols using Configuration Manager too.

--
Ekrem Önsoy
Markus Bala replied on 12-Mar-09 11:13 PM
. 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: SQL Network Interfaces, error: 28 - Server doesn't support

requested protocol)"



Network protocols are disabled in SQL Server 2005 Express by default so we need to enable TCP/IP:



# Launch the SQL Server Configuration Manager



# Expand the "SQL Server 2005 Network Configuration" node



# Left click the "Protocols for SQLEXPRESS" node to view the supported protocols



# Right click the "TCP/IP" protocol and select "Enable"