Troubleshoot Connectivity Issue in SQL Server 2005 - Part III

Troubleshoot Connectivity Issue in SQL Server 2005 - Part III

Part III – Connection Fail when SqlClient connects to Sql Server 2005

When you connect to SQL Server 2005 either using "SQL Server Managment Studio" or any application compiled with .NET Framework 2.0, you are using SqlClient provider(Access data from within a CLR database object by using the .NET Framework Data Provider for SQL Server.)


Error Message 1:

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)

Troubleshoot:
1) Make sure your sql service is running, use either "net start" or "sc query <InstanceName>" or run services.msc, check status of the server; If server start fail, go to ERRORLOG to see what happened there, fix the problem and restart server.

2) You might explicitly use "np:"prefix which ask for connect through named pipe. However, client can not connect to server through the pipe name that specified.Double check the server is started and listening on named pipe if you enabled Named Pipe. One way is that see the ERRORLOG of the server, search follow keywords:

Server named pipe provider is ready to accept connection on [ \\.\pipe\sql\query ] or [\\.\pipe\mssql$<InstanceName>\sql\query]

Notice that "sql\query" is the default pipe name, so you need to know server is listening on which pipe name. eg: if you specify server pipe name is "sql\query1", then you would see in the errorlog that server listening on [ \\.\pipe\sql\query1 ], and go to SQL Server Configuration Manager, click client Named Pipe properties, see whether the pipe name is same with the one server listening on.

3) You might specify named pipe protocol in connection string, but did not enable named pipe on the server, check ERRORLOG.

4) You might use FQDN/IPAddress/LoopbackIP to connect to the server when only shared memory was enabled, you can change to <machinename> to resolve this.

5) You might explictly specify "lpc:" prefix in your connection string, but shared memory was not enabled. To resolve this, either remove the prefix as long as named pipe or tcp was enabled or enable shared memory.

Error Message 2:

A connection was successfully established with the server, but then an error occurred during the pre-login handshake. 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: 0 - No process is on the other end of the pipe.)

1) You might explicitly use "np:"prefix which ask for connect through named pipe and specify FQDN/LoopbackIP/IPAddress as server name in the connection string.
2) You might use FQDN/IPAddress/LoopbackIP to connect to the server.

To resolve 1) and 2), you can specify <machinename> instead of FQDN/IPADress/LoopbackIP.

Error Message 3:

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: Shared Memory Provider, error: 40 - Could not open a connection to SQL Server)

Troubleshoot:
1) You might explicitly use "lpc:"prefix which ask for connect through shared memory. Either server instance was not started successfully or shared memory was not enabled on the server.To resolve this, you remove "lpc:"prefix in your connection string as long as Server is listening on other protocols or enable shared memory and restart server.

2) You explicitly use "lpc:"prefix and connect to a local named instance through form [./(local)/localhost/<machinename>]\<InstanceName>, but Sqlbrowser service was not started. To resolve this, you need to enable sqlbrowser.

3) You might connect through "lpc:" which not includes any server name, to fix this, add correct server name in your connection string.

Error Message 4:

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: TCP Provider, error: 0 - No connection could be made because the target machine actively refused it.)

Troubleshoot:
1) You might explicitly use "tcp:"prefix which ask for connect through TCP/IP, however either server was not listening on TCP/IP, to resolve this, either remove "tcp:"prefix in your connection string or enable tcp protocol.

2) You might not connect through the exact port that server is listening on, to verify this, go to SQL Configuration Managner
choose "Protocols for <InstanceName>" and click properties for TCP/IP, see which port is configured for server listening and then try connect through the port, like in connection string "tcp:<machinename>,<portnumber>".

3) The instance that you want to connect through TCP was not started, check server ERRORLOG and restart server.

Error Message 5:

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: 26 - Error Locating Server/Instance Specified)

1) You might have named pipe or tcp enabled and connect to a named instance, but SQL Browser service was not started or enabled. To enable browser, First, Use net start or go to sql configuration manager(SSCM), check whether sqlbrowser service is running, if not, start it; Secondly,You still need to make sure SqlBrowser is active. Go to SSCM, click properties of sqlbrowser service -> Advanced-> Active “Yes” or “No”, if sqlbrowser is running but is not active, the service would not serve you correct pipe name and Tcp port info on which your connection depends.

Error Message 6:

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: 41 - Cannot open a Shared Memory connection to a remote SQL server)

1) You might explicitly use "lpc:"prefix and connect to a named instance but specify FQDN/LoopbackIP/IP as <servername>, eg, your connection string looks like "lpc:<FQDN>\<InstnaceName>" or "lpc:127.0.0.1\<InstanceName>"..

2) You might explicitly use "lpc:"prefix and give the wrong server name in your connectionstring, eg: "lpc:xx" <xx> is not the hostname of your machine.

Error Message 7:

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)

1) You might explicitly use "np:" prefix in your connection string and try to connec to a named instance, but named pipe was not enabled on the remote server, to resolve this, enable the remote named pipe and restart instance or remove "np:"prefix if remote server is listening on TCP/IP.

2) You might explicitly use "tcp:" prefix in your connection string and try to connec to a named instance, but TCP/IP was not enabled on the remote server, to resolve this, enable the remote TCP/IP and restart instance or remove "tcp:"prefix if remote server is listening on Named Pipe.

Error Message 8:

An error has occurred while establishing a connection to the server. When connectiong 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:TCP Provider, errror:0-A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.)

1) This is because connection blocked by Windows firewall. To resolve this, take follow steps:

a. Enable SqlBrowser, see the info in Message 4. Plus, add sqlbrowser.exe into Firewall exception list: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile\AuthorizedApplications\List
b. Add Tcp port to Firewall exception list. (eg, Name-1433:TCP, Value-1433:TCP:*:Enabled:Tcp 1433).
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile\GloballyOpenPorts\List.For more detailed operation, see http://support.microsoft.com/default.aspx?scid=kb;en-us;287932

Summary:

1) In any case, SqlClient should be able to connect to SQL Instance through any of the protocols(Shared Memory/Named Pipe/TCP) as long as SQL Instance was started successfully.

2) And if you speculate any protocol in connection string ("lpc:"/"np:"/"tcp:"), the error message would display "<Protocol> Provider, error <Num1> -....<Num2>." <Protocol> stands for "Shared Memory" or "Named Pipes" or "TCP"; If you do not speculate
any protocol, the error message indicates that connection fails when connecting through specific <Protocol>.

3) In the error message format for SqlClient, please notice two different error number. <Num1> stands for internal error thrown out by SQL Protocols, <Num2> is the OS error(eg: 233 - No process is on the other end of pipe). When you see <Num1>=0, that means the connection fails due to OS error not caused by SQL Protocols, under this situation, you can use "net helpmsg" to check specific OS info.

Finally, if you were developing .NET framework application and came across above issues in your client app, the best way is first try SQL Server Management Studio to connect to SQL Server using the exact same connection string in your app, and watch the error message, normally, there is additional error info at the end of error string, eg ( Microsoft SQL Server, Error:87) which gives you clue(net helpmsg 87) that problem inside your connection string.

MING LU

SQL Server Protocols

Disclaimer: This posting is provided "AS IS" with no warranties, and confers no rights

 

Leave a Comment
  • Please add 6 and 8 and type the answer here:
  • Post
  • PingBack from http://www.hilpers-esp.com/404764-error-al-querer-conectar-una

  • PingBack from http://www.keyongtech.com/2079472-error-40-a

  • Out of nowhere, we got this error and are trying to figure out what the issue is.

    OLE DB provider "SQLNCLI" for linked server "<server name>" returned message "Communication link failure".

    Msg 64, Level 16, State 1, Line 0

    TCP Provider: The specified network name is no longer available.

    Any help would be greatly appreciated.

    Thanks,

    KV

  • Bad public user name or password. Database Server Error: Named Pipes Provider: Could not open a connection to SQL Server [53].

    I am getting this message on installing Primavera

    Can anybody help me...?

    anandc1@gmail.com

  • Hello,

    I am building a SQL 2008 cluster. On the initial node that I ran the install on, SQL is running fine. However, whenever I try to fail it over, I am receiving these messages in the event viewer:

    FallBack certificate initialization failed with error code: 1.

    I do not want to use certificates. Is there any way I can bypass this?

  • Help!!!  We are getting the following message on a SQL Server 2005 box.  I could find anyone else who has had this problem.

    A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: SSL Provider, error: 0 - The client and server cannot communicate, because they do not possess a common algorithm.)

  • Our problem has been resolved.  Someone had made some SSL registry changes which affected SQL Server and other applications.

  • I have a very unique issue related to Error: 26 - Error Locating Server/Instance Specified, I am hoping that your expertise may help.

    I have a cluster running SQL Server with two instances, listening on ports 2300 and 2305. Connecting to the instances within the network works fine by either using VSPHOST1A\PHOST1A or VSPHOST1A,2300. I can also from within the network use VSPHOST1A.name1.name2.name3.com\PHOST1A or VSPHOST1A.name1.name2.name3.com,2300.

    The problem is I can not access the SQL Server from another domain/network (within the same company) using the fully qualified name\PHOST1A, it only works with the port. I am however able to get both methods under the fully qualified name to work with non clustered instances. It is definitely cluster-related, any thoughts?

    Thanks!!

  • Hi Andrew,

     It sounds like you very likely have the problem discussed on this blog entry: http://blogs.msdn.com/sql_protocols/archive/2006/02/27/unable-to-connect-to-a-sql-server-named-instance-on-a-cluster.aspx

  • MMC cannot open the file c:\program files\microsoft sql server \80\toolse\binn\sql srver enterprise manager.msc

  • PingBack from http://backyardshed.info/story.php?title=sql-protocols-troubleshoot-connectivity-issue-in-sql-server-2005

  • PingBack from http://greenteafatburner.info/story.php?id=1584

  • Hi

    If you wants to know how to enable remote connections

    in sql server 2005 pls visit this

    http://aspnetmembershipprovider.blogspot.com/2009/02/eanble-remote-connections-on-instance.html

    Regards

  • Solution:

    After many tries in diferent ways we found the solution in simply change the connection string in the web config file. We take out:

    "Persisty security Info=True; User ID=theuser; Password=thepass"

    and simply keep:

    <add name="TheLocalNet" connectionString="Data Source=theserver;Initial Catalog=theDataBase;Integrated Security=True" providerName="System.Data.SqlClient"/>

  • TITLE: Microsoft SQL Server Management Studio

    ------------------------------

    Failed to retrieve data for this request. (Microsoft.SqlServer.SmoEnum)

    For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&LinkId=20476

    ------------------------------

    ADDITIONAL INFORMATION:

    Failed to connect to server 192.168.0.1. (Microsoft.SqlServer.ConnectionInfo)

    ------------------------------

    A connection was successfully established with the server, but then an error occurred during the login process. (provider: TCP Provider, error: 0 - The specified network name is no longer available.) (Microsoft SQL Server, Error: 64)

    For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=64&LinkId=20476

    ------------------------------

    BUTTONS:

    OK

    ------------------------------

Page 13 of 15 (217 items) «1112131415