Regular readers of my blog are aware of the fact that I have written about this subject umpteen times earlier, and every time I have spoken about a new issue related to it. Few days ago, I had redone my local home network. I have LAN setup with wireless router connected with my four computers, two mobile devices, one printer and one VOIP solution. I had also formatted my primary computer and clean installed SQL Server 2008 into it. Yesterday, incidentally, I was sitting in my yard trying to connect SQL Server located in home office and suddenly I stumbled upon the following error. Finding the solution was the most infuriating part as it consumed my precious 10 minutes.
Let us look at few of the common errors received:
An error has occurred while establishing a connection to the server.
(provider: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 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: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 1326)
I eventually found the resolution to this error on this blog itself; so I was saved from hunting for the solution. I am sure there are a number of developers who had previously fixed this error while installing SQL Server 2008 or SQL Server 2005 but in due course forgot the right solution to this error. This is just a quick refresher. Make sure to bookmark this as you never know when you would need this solution.
Let us check into the steps to resolve this error.
1) SQL Server should be up and running.
Go to All Programs >> Microsoft SQL Server 2008 >> Configuration Tools >> SQL Server Configuration Manager >> SQL Server Services, and check if SQL Server service status is “Running”.
In addition, ensure that your remote server is in the same network. Run “sqlcmd -L” in your command prompt to ascertain if your server is included in your network list. You can even find tutorial for the same here SQL SERVER – Find All Servers From Local Network – Using sqlcmd – Detect Installed SQL Server on Network.
I have confronted numerous situations when these nerve-wracking errors crop up, and most of the time when I try to troubleshoot I notice that SQL Server services are neither running nor installed. If SQL Server is not installed as default instance SQL Server Browser should be running together with it; we will explore this further in Topic 5.
2) Enable TCP/IP in SQL Server Configuration
When two or more SQL Servers are connected across network they do all communication using TCP/IP. The default port of SQL Server installation is 1433. This port can be changed through SQL Server Configuration Manager. TCP/IP should be enabled for SQL Server to be connected.
Go to All Programs >> Microsoft SQL Server 2008 >> Configuration Tools >> SQL Server Configuration Manager >> Select TCP/IP
Right Click on TCP/IP >> Click on Enable
You must restart SQL Server Services for all the changes to take effect. Right click and go to menu properties to select location where default port of SQL Server can be changed.
3) Open Port in Windows Firewall
Windows Firewall is very efficacious in protecting the Operating system from all sorts of malicious attacks. By default, many of the ports and services are refrained from running by firewall. Time and again, SQL Server ports are not open in firewall as well. All the ports on which SQL Server is running should be added to exception and firewall should filter all the traffic from those ports. As described, by default SQL Server runs on port 1433, but if default port is changed then the new port should be added to exception. If SQL Server has named instance (another instance besides default instance) is installed, SQL Server browser should also be added to the exception, as described in Step 7.
Go to Control Panel >> Windows Firewall >> Change Settings >> Exceptions >> Add Port
Make the following entries in popup “Add a Port” and click OK.
Name : SQL
Port Number: 1433
Protocol: Select TCP
4) Enable Remote Connection
Enabling remote connection is another important, yet oft-neglected step that is frequently missed by database administrators while setting up SQL Server. If this feature is turned off SQL Server will function smoothly on local machine, but it will let another server connect to it remotely. By default this feature is ON in SQL Server 2008.
Right click on the server node and select Properties.
Go to Left Tab of Connections and check “Allow remote connections to this server”
5) Enable SQL Server Browser Service
If SQL Server is not installed as default instance but instead installed as named instance and also if there is no specific TCP/IP port configured, it will give rise to the error that is being discussed in this article. If SQL Server Browser service is enabled, it will allow the server to be connected through dynamic TCP/IP port. Enabling this service is a one-time process, as on enabling it once it will apply to all the instances installed on the same server.
Go to All Programs >> Microsoft SQL Server 2008 >> Configuration Tools >> SQL Server Configuration Manager >> SQL Server Browser
Right Click on SQL Server Browser >> Click on Enable
6) Create exception of sqlbrowser.exe in Firewall
As elucidated in Step 6, sqlbrowser service needs to be enabled for named instance. Windows Firewall may prevent sqlbrowser.exe to execute. So, it is imperative to add exception for the same in windows firewall.
Search for sqlbrowser.exe on your local drive where SQL Server is installed. Copy the path of the sqlbrowser.exe like C:\Program Files\Microsoft SQL Server\90\Shared\sqlbrowser.exe and create the exception of the file in Firewall, as delineated in Step 3.
7) Recreate Alias
It is getting quite common to create alias of SQL Server and use it in application. This will ensure that in future if any physical SQL Server has to be moved, it will not be required to change any code or connection string. You can simply create alias with the same name pointing to different SQL Server and it will start working instantaneously. I have observed that a couple of times due to internal error while recreating alias this error was fixed.
Go to All Programs >> Microsoft SQL Server 2008 >> Configuration Tools >> SQL Native Client 10.0 Configuration >> Aliases
Delete the alias that is giving problem and recreate it with identical parameters.
I have tried my best to include all the methods of fixing this error and if I have missed any, please leave a comment and I will be very glad to include them here. I have put in my effort to encompass this issue in one article that needs to be refereed when any connection error comes up.
Watch SQL in Sixty Seconds video to Resolve Connection Error:
[youtube=http://www.youtube.com/watch?v=1k00z82u4OI]
Reference : Pinal Dave (https://blog.sqlauthority.com)
658 Comments. Leave new
Excellent! Thank you so much. No. 6 to fixed my issue.
Wish I came across this article first
Thanks a lot.
Items 5 & 6 fixed my problem.
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 – No connection could be made because the target machine actively refused it.
Its Working now … thanks :)
Nicely covered. But there is more to it than meets the eye. This problem cropping up say from 2005 to 2012 gives me the impression that there is something basically not well done. Perhaps you should update this to cover SQL Server 2012. In Microsoft world, things can only get screwed up more.
Yes my dear pinaldave sir
iam also facing the same error u faced ,but the situation is different.in advance i thanking you and hopes your help
i am managing two hosting in godaddy like hostA,hostB asp.net 4.0 ms sql 2008
situation where i am facing this error is while i am trying to insert some datasto the sql server of hostB from hostA
given is my codes
SqlConnection con;
SqlCommand cmd;
con = new SqlConnection();
cmd = new SqlCommand(My ConnectionString with (Data Source,Initial Catalog,User ID, Password));
cmd.Parameters.AddWithValue(“@ImageID”, str);
cmd.Parameters.AddWithValue(“@ImageName”, imgName);
cmd.Connection = con;
cmd.CommandText = “insert into Contents.ContentImageList values(@ImageID,@ImageName)”;
con.Open();
// int count = cmd.ExecuteNonQuery();
//con.Close();
while executing con.Open() the problem arising
i googled lot for solution,still iam getting the error, what more i should do ?
Thanks…
Items 5 fixed my problem.
Its great….! its working now for me.
I just installed SQL Server 2008 Management studio Express on my Win xp machine.
i tried connecting to local machine using :
.\sqlexpress, (local)\sqlexpress, or .\SQLExpress, MyPCNAME\SQLExpress
nothing is working, getting this error:
—————————–
Cannot connect to PC-NAME\SQLEXPRESS. 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: SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified)
I still have the error. After I have done above. My environment is cluster in Windows Server 2008 R2 and SQL Server 2008 R2, but I still error.
“A network related or instance specific error occurred while etablere a connection to SQL Server. The server was not found or was not accessible. Verify att instance name is correct and att SQL Server is Configured at lade remote connection. (Provider: Names Pipes Provider, error: 40 – Could not open a connection to SQL Server)
I had this error with a new server installation. This post helped me to fix it. Thank you! :D
This is awesome! I was looking to solutiion for the error connecting to instance of SQL Server 2008 R2 for a long time. Any blog was pointing to about same search path. Only here, and the last point – aliases – did a trick for me. Feels great. Thank you Pinal fo all you do.
very very nice thanq so much
Dude you are amazing! Fix my problem easily.
Thank you very much, this help me a lot,
Thanks very much
Thank you very much for help!!!
I love it. This was very helpful!
I followed every step in your blog trying to get SQL Server 2008 to function properly, and I still get the following error:
(provider: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server).
I can see the server from my VB.NET application but when I try to connect to it to get a list of DBs I get the above mentioned error.
This is very frustrating.
Dear Pinal
The scene is that
I have windows server 2003 and sql server 2000 installed, i have already set all the necessary setting.
disabled the firwall
enabled the tcp/pipes protocols
added the sql server tcp port in the firewall exception
and the 2nd that i have already installed the sqlclient over the client side other computer , that i need to connect to that server.
but when i connect i recive an error message:
Microsoft SQL Server Error
SQLSTAT=08001
Named Pipe Provider:can not connect to sql server.
Error: [1326]
Please help me in this regards
KP