In continuing with the theme of understanding error messages I'll discuss the "login failed" messages that are surfaced by the client and written to the server's error log ( if the auditlevel is set to log failures on login which is the default) in the...

One of the more visible changes we made in connectivity space for SQL Server 2005 was enhancing error messages reported to the user in case of connection failures. I have seen several cases over the last several months, and in this post I would like to...

This post provides some tips to troubleshoot Sql Server connection problems based on various displayed error messages. And, I will describe connection problems according to different client stack: SNAC/MDAC/SQLClient. Thus, there are 3 parts for this...

Users often see this error message when connection to a SQL Server and don't know where to start to solve the problem. In most forums, people says this is because remote connection is not enabled on the server. This is not exactly correct. Actually, this...

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...

This error was most frequently hitted by our customers, and in this post, give a brief summary of troubleshooting tips for this specific error message. First, take a look at below MSDN forum link lists about this topic: http://forums.microsoft.com...

Please visit http://blogs.msdn.com/sql_protocols/archive/2005/10/22/483684.aspx for troubleshooting connection problems when SNAC(SQL Native Client) connect to SQL Server 2005. Part II – Connection Fail when MDAC connects to SQL Server 2005 Use...

Understanding the error message: “Login failed for user ''. The user is not associated with a trusted SQL Server connection.” This exact Login Failed error, with the empty string for the user name, has two unrelated classes of causes, one of which...

The “Cannot generate SSPI context” issue is described by http://support.microsoft.com/?id=811889 in general. In this post I will discuss one daunting case of “Cannot generate SSPI context” error message when failing to connect to SQL server. In most related...

SQL Server 2005: “Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'”. SQL Server 2000: "Login failed for user "(null)". Reason: Not associated with a trusted SQL Server connection". The errors listed above is very typical when deploy linked...

With shipping SQL Server 2005, we heard from customer feedback about suffering make successful remote connection against SQL 2k5, plus, if running SQL Server on XP/WIN2K3/VISTA behind firewall, such problem occurs more frequently and harder for customer...

In this post, I focus on how NTLM and Kerberos are applied when connecting to SQL Server 2005 and try to explain the design behavor behind several common issues that customers frequently hit. On this page: Kerberos VS NTLM. Requirements for Kerberos...

We have been seeing and trying to resolve SQL connectivity issue all the time. I guess it would be helpful if we can put some guidance on how to resolve connectivity issues. Here comes a proposal based on my experience. Basically, when you failed...

Recently, we answered a lot of customer questions about how to make a successful connection to SQL Express 2005 through MSDN forum and our blogs. Here, I collect basic info about it and a brief guide of making local and remote connection to SQL Server...

We have been seeing several occurrences where users failed to connect to SQL Server named instance on cluster. The error messages are usually as follow: For SNAC: C:\>osql -E -S cluster\inst [SQL Native Client]SQL Network Interfaces: Error...

Kerberos is a widely accepted network authentication protocol that is used to provide a highly secure method to authenticate users. Reliance is placed upon a trusted third party called the Key Distribution Center (KDC) to facilitate the generation and...

In this post, I am trying to list out potential cause and general solution to this specific error when you are making connection to SQL Server 2005. First, It is due to TCP connection fail, since you can tell from the title, "TCP Provider: .xx", which...

Networking protocols are disabled by default in SQL Server Express. The error message you will get when trying to connect from SQL Native Client will look like this “An error has occurred while establishing a connection to the server when connecting...

I recently worked on three customer issues. In all those cases, customers were not able to backup databases using Microsoft Volume Shadow Copy Service (VSS). MSDEWriter does not show up with “vssadmin list writers”. And VSS logs the following error message...

I've seen this problem posted a couple times on the MSDN forums so I'm including the problem and the solution here. The MSDN SQL Server Data Access Forum is available at: http://forums.microsoft.com/msdn/ShowForum.aspx?ForumID=87 . If you see the following...

Users sometime see the “Cannot Generate SSPI Context” error message. A very good source for troubleshooting the error is http://support.microsoft.com/default.aspx?scid=kb;en-us;811889 . You can also find good information at Using Kerberos with SQL Server...

This error message is the most frequent error message when connecting to SQL Server. You see this error message when you use SqlClient. In SNAC, the error message is slightly differently as follows: C:\>osql -E -Syourserver [SQL Native Client]Named...

Lately we have noticed many misunderstandings surrounding the usage of the Data Source keyword in connection strings, caused by people generalizing from an example demonstrating a connection string for local connectivity and creating their own connection...

SQL Server 2005 could fail to bring up due to various causes, there are several great blogs that talk about different reason: http://blogs.msdn.com/sql_protocols/archive/2006/01/10/511330.aspx http://blogs.msdn.com/sql_protocols/archive/2005/10...

The client error messages related to this post are the followings. For MDAC client, [DBNETLIB]General network error. Check your network documentation. [DBNETLIB]ConnectionRead (recv()). For SNAC client, For SNAC client, “ TCP Provider:...