So we have SQL Server 2008 R2 Express running on a local server, and a bunch of machines on the same LAN use a program I wrote in C# to access said server.
All the machines in the building except one can connect quite happily.
Connection string is:
Data Source=[IP address here],53535\SQLEXPRESS;Initial Catalog=EMS_Main;;User ID=EMSUser;Password=[password here];
Exact error message is:
"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - An invalid argument was supplied.)"
Struggling to believe the 'invalid argument' bit, given that all other machines connect quite happily.
SQSL is definitely configured to accept remote connections, instance name is definitely correct.
The problem machine can connect using SQLSMS, but not via C#.
Disabling firewall on the problem machine makes no difference.
Everything seems to have been working fine on the problem machine up until a Windows 10 update a couple of days ago.
EDIT: An update on this: I now have two machines with this issue, and they both seem to have only developed it after Windows 10 updated to version 1803. All the pre-1803 machines still work fine.
Can anyone shed any more light on this please?
For anyone else hitting this issue, I discovered that this was happening because the client application was being run from a shared drive, and Windows 10 update 1803 must have some security update in it that causes this problem (only machines running 1803 were affected).
Running the application from the machine's hard drive solved the problem.
I'd still like to know a technical explanation for this, even though the problem is solved.
I have the same issue. A dig deeper and discovered that this happened after installing an update (May 8, 2018—KB4103721). Try to uninstall this update or use named pipes instead tcp.
I'm running SQL Server 2014 Express and using the SQL Server native drivers for the connection from my VS.net code. These are both on my Win10 machine.
Suddenly, in the last week or so, I've been receiving errors when my code attempts to connect. Of course the dialog doesn't allow cut-n-paste, so helpfully this is correct:
Named Pipes Provider error 40 - Could not open connection to SQL Server
This only happens about 1 in 10 times that I run the app. If I simply stop it and re-run it, it instantly connects. Another machine in the office running Win7 and SQL Server 2012 started showing the same behaviour, but fails all of the time now.
Note: yes, the server is running, the firewall is configured properly, as is the server's connections, the browser is up, etc. It's important to note that these would cause it to fail 100% of the time.
Does anyone have any ideas what's going on? Was there a recent driver update that might cause this perhaps?
I just built a new machine after my old one crashed a few days ago. I'm running Windows 7. I installed SQL Server 2012 Express as well as SQL Server Development Edition with Tools.
After installing, I made sure I could connect to both the Express version, local Dev server as well as multiple remote servers. Everything was great.
This morning, I installed Visual Studio 2012. Since doing this, I can still connect to my Local servers (Express and Dev), but I can't connect to the remote servers. The error I get is this:
A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: SSL Provider, error: 0 - The wait operation timed out.) (.Net SqlClient Data Provider)
I've searched for issues, and while I've found some similar to this, not many mention Visual Studio, and none offer a solution.
UPDATE
I found I can connect using Named Pipes. The problem then is that not all my servers are configured to allow Named Pipes.
Visual Studion Connection Related Error:
netsh winsock reset
Run this command in command prompt. That will Fix Connection Related Error in Visual studio 2012
I think you'll need to look in your SQL server configuration manager and make sure TCP/IP is enabled for the database instances your interested in.
It isn't by default if I remember rightly.
If you're ok locally, have you read this post?
An error occured during the pre-login handshake
As other users are experiencing this problem, I thought I would add the solution I found.
The utility lspfix.exe found a break in the Layered Service Provider (LSP) chain. I applied the recommended fix and I was up and running again.
The fix was recommended by the lspfix.exe application. It's a very simple tool to use and it found the problem quickly. Here is the url to the tool.
http://www.cexx.org/lspfix.htm
I have been using SSMS and LinqPad both for months to connect to SQL Azure instances without issue. Suddenly this week, linqpad stopped connecting, consistently timing out and displaying this error message: "A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: SSL Provider, error: 0 - the wait operation timed out.)"
At first, it was just LinqPad. But soon after I started experiencing the same issue with SSMS 2012. It showed the exact same error message (slightly different dialog).
I've confirmed that this isn't a firewall rule issue. My IP has been allowed through the SQL firewall for months, and I can still connect using the same credentials using SQLCMD and I can run queries.
Any ideas? Why would SSMS and LinqPad both take a big dump while SQLCMD still works?
I finally found the solution to this (I think I may have found it via https://stackoverflow.com/questions/13420770/pre-login-handshake-error-connecting-directly-to-sql-azure). I installed some completely unrelated software about the time that things stopped working. As it happens, said software also installs - silently - some bundled software that leaves you with custom Winsock LSPs in place, which means the system is then afflicted by an issue reported to Microsoft and addressed in KB 2568167. Fortunately, I didn't have to manually remove the LSPs because I was able to uninstall the unwelcome software (Sendori!).
Did you look at the connectivity troubleshooting guide for SQL Azure?
http://social.technet.microsoft.com/wiki/contents/articles/1719.windows-azure-sql-database-connectivity-troubleshooting-guide.aspx
Have you also installed .NET 4.5 recently/in that week time frame? Have you checked your SQL Connection to make sure that SSL encryption is off?
Yes folks, it's this one again.
"A connection was successfully established with the server, but then
an error occurred during the login process (provider: TCP Provider,
error: 0 - An existing connection was forcibly closed by the remote
host.)"
I'm sorry... I have Google'd this, I have read the other StackOverflow articles on this problem, and I have tried all kinds of suggestions, but nothing works.
Here's a few notes about what we're seeing.
This issue occurs occassionally in SQL Server Management Studio itself (doing any kind of database activity... getting a list of tables in a database, having a look at a Stored Procedure, etc)
It also happens in Visual Studio 2010 itself, when it is trying to get data from the servers (e.g. when creating a .dbml file, etc)
It also sometimes happens in our .Net (ASP, WPF, Silverlight) applications.
Our SQL Server 2005 & 2008 servers are all based on virtual machines in data centres around the world, and we see sometimes this error on each of them. But most of the time, they all work absolutely fine.
When the error does occur, we can just "retry" what caused the error, and then it'll work fine.
We think.. if we have an IIS Web Server in a data centre in a particular city, and it accesses a SQL Server in the same data centre, then we don't see the issue.
We think.. if we connect to the servers, and specify the UserID and Password to use, it causes this error much more frequently than if we just use Active Directory authentication.
Put all that together, and it sounds to me like some kind of network issue.
But can anyone suggest what to look for ?
This isn't a bug in our .Net applications, as even SQL Server Management Studio "trips up" with this error.
It's baffling us.
Just in case anyone else hits this issue, we finally found the solution.
Our company uses Riverbed software to compress data, when it's being passed between locations, and this was somehow causing some connections to get dropped.
Our IT gurus found a configuration setting which finally fixed this issue.
I believe there's a setting in there to turn off compressing results from SQL Server (or something like that). That fixed it for us.
It could be any number of network issues. ANYTHING that prevents the code from reaching the server even for the few miliseconds it takes to make one query.
it could also be the result of a failover. When we went from a single SQL Server to a clustered environment, we'd see this happen during a failover. In this case, it turned out to be our Connection Pooling. In essence, the SQL cluster has a controller and two servers behind it. A and B.
Say our web app is using server A just fine, Connection pooling creates a connection on both sides. The server is aware of it, and the web app is aware of it. Once the cluster fails over to the second server, the web app is aware of the connection but server B is not, so we get an error.
The point is, any possible cause of network issues imaginable may be the cause. DOS attacks on the server, man-in-the middle attacks intercepting and changing traffic. Someone trips on an ethernet cable and it's loose in the jack. You name it, if it can cause a connection issue, it could be the cause.
Your issue also sounds like one we had recently - we also have a virtual environment, wih software that moves VMs from one host to another as needed for load balancing. Every so often, we'd get bombarded with the same error. It turned out to be an issue with the NIC drivers on one of the hosts, so whenever a VM moved to that particular host, errors would occur.
It's really not a programming issue. It's an environment issue, and you need trained professionals with direct access to your environment to research and resolve this.
My problem was that I was inadvertently using a wireless network to connect to our network because the Ethernet cable was faulty. This after repairing SQL Server, running a Winsock reset as recommended elsewhere ...
I am experiencing the same issue and our app interfaces with a several Azure SQL DBs. I believe (same as you) I do not have a bug in the C# code to cause this issue. We've solved it by a simple for loop containing an extra attempts to try to connect to the Azure SQL again if the previous attempt fails and then run the query.
Most of the time everything runs fine but sometimes we can see the loop kicked-in and on the 2nd or 3rd time it executed properly without the below mentioned error. After that we see in the log file the error below for all the unsuccessful attempts:
A connection was successfully established with the server,
but then an error occurred during the login process. (provider: TCP
Provider, error: 0 - An existing connection was forcibly closed by the
remote host.)
Even though this is a less-then-pretty solution, it allowed us to run our app without interruptions. I know you've mentioned that trying to connect again (to introduce some connection-failure tolerance) solves the problem and unfortunately this is the only correct solution I found so far as well.
I should mention that we have tried many debugging strategies to figure this out. Right now it all points to the availability of the database we are trying to connect to i.e.: It happens if the number of allowed DB connections is exceeded. (or so it seems at this time)
Turn off your VPN
My Problem fixed by turn off VPN
It was happening in our code when we were opening the dbconnection for oracle and were passing DBtype as SQL in our database object.
in my case - the error was Microsoft first suggestion:
Client is connecting with an unsupported version of the SQL Server Native Client.
In our case, We got this error when we updated sql server to sp3. We were not able to connect to the database from SSIS package.
We updated the native client and configurations. We were able to connect.
link to download the native client - https://www.microsoft.com/en-us/download/confirmation.aspx?id=50402
Link for configurations settings and further troubleshooting - https://learn.microsoft.com/en-us/previous-versions/sql/sql-server-2008-r2/ms187005(v=sql.105)
Hope it helps.
Cheers!
Had the same type of issue. In my case it was a bit more complicated... I could connect to “ServerA” from “ServerB” via SSMS, but it would fail with sqlcmd. The error was the same:
Sqlcmd: Error: Microsoft SQL Server Native Client 11.0 : TCP Provider: An existing connection was forcibly closed by the remote host.
I could also connect from “ServerC” with both SSMS and sqlcmd. The following are the versions on the VMs:
ServerA: Microsoft Windows Server 2012 R2 Datacenter / Microsoft SQL Server 2012 (SP3-CU10) (KB4025925) - 11.0.6607.3 (X64)
ServerB: Microsoft Windows Server 2012 R2 Datacenter / Microsoft SQL Server 2012 - 11.0.5058.0 (X64)
ServerC: Microsoft Windows Server 2012 R2 Datacenter / Microsoft SQL Server 2012 (SP3-CU10) (KB4025925) - 11.0.6607.3 (X64)
Bottom line was the “unsupported version”. I noticed a mismatch of “sqlncli11.dll” between ServerC and ServerB, so I copied it to the System32 folder. After this, sqlcmd worked like a charm. Below were the versions in my case:
Failed:
FileVersion: 2011.0110.5058.00
ProductVersion: 11.0.5058.0
Worked:
FileVersion: 2011.0110.6607.03
ProductVersion: 11.0.6607.3
I was working on 2 projects at the same time (on 2 different machines) and both used SQL Server.
When i disconnected SQL with 1 machine the errorMessage went away. Probably you can mess around with IP-adresses too to fix the problem.
In my case I was seeing this error intermittently from a .Net application connecting to a SQL server located in the same server room. It turned out that some of the databases had auto close turned on which caused the server to close the connections in the pool. When the application tried to use one of the pool connections that had been closed, it would throw this error and I saw a log message on the SQL server that the database it was trying to connect to was being started. Auto-close has now been turned off on those databases and the error hasn't been seen since.
Also, having auto-close on is the default behavior for SQL Express databases and these were originally created on an Express instance during testing before being migrated to the production server where we were seeing the errors.
this answer is for those how have this problem with Azure Sql server database.
It happens when you reach mat pool
first remove Persist Security Info=False from connection string
second check your database plan in azure portal and increase the PTUs of your database plan.
In SSMS "Connect to Server" screen click Options, then on "Connection Properties" TAB change "Network protocol" to "Named Pipes"
Try this -
Click Start, point to All Programs, and click SQL Server Configuration Manager.
Click to expand SQL Server Network Configuration and then click Client Protocols.
Right-click the TCP/IP protocol and then click Enable.
Right-click the Named Pipes protocol and then click Enable.
Restart the SQL server service if prompted to do so.
I have had this issue a couple of time already, and I've fixed by reducing the MTU size. Often 1350, 1250, etc on my network interface.