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
Dear,
I have same problem i.e. unable to connect server (using win authentication) but as you suggested also can’t work b’coz it doesn’t have option for configuration (i.e. configuration tool) . Is this pb of setup file (43.2 MB) …?
Error Msg:
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)
Great Post.
thanks’ very much
Hello Mr. Dave
This is the first time i am sending a post to you. But I always follow your advices. your advices helped me lot when no one was near me to suggest.
today i faced a problem that when i want to connect to sql server 2008 on the windows server 2008 then in the udl file the server name is showing but when i connect through windows authentication or sql authentication then it is giving me an eror as sql server doesnot exist or access is denied.
but when i tried from other pcs i can connect to the database and my windows application is working fine.
all the pcs are in the same network and in the same domain also.
but why then the problem is only for this 1 pc only.
i checkd all the issues above which you suggested me but also the same problem.
please guide me.
Thanks for the help. I got to the TCP/IP part and it was disabled.
I followed your steps, but still couldn’t attach. Found elsewhere to check the port number SQLExpress was using. Turns out SQLExpress was using dynamic ports. I forced it to use 1433, and (including all the above instructions), could finally connect. Yeah!
Hi,
The servers need to have Static IP. Because we tried to connect this server from the outside not in the same network.
Please advise.
Regards,
Mike
THANKS
This article is life saving
Thanks alot
You can’t imagine how do you help me at this moment, it’s an extraordinary article, i thank you sooooooooo much, thaaaaaaaaaaaaaaaanx
Mr. Dave – Thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you!
your fix provided the tip to allow the sqlbrowser.exe thru the firewall. i’ve only been looking for this resolution for…um…a couple of weeks now. Your Fix worked with 2008 R2 & SQL 2012 RC0 – that I was trying to access via Office 2010 Access database front end.
Happy Holidays
thanks. I was searching for the solution of error 10061 for hours. My mssql server was stopped and works fine after I initiated mssql server. I feel like so dumb now.
thanks.
Thanks All
Hi sir,
Sir i have 50 flat files . I want create automatically tables in sql server using SSIS loop or use any statement sir But i want at time to create the table and automatically inserting the data throughout each flat file .
Finally i want to get massage 50 tables created and related columns and data also
Hi Expert:
I have install sql server 2005 on microsoft server 2008.and also restored database.
I have create alias with as “expodb”. And it working fine for me during login in sql server management studio.
when try to connect the database using server name or alias in c sharp connection string it gives me “sql server error :40 “.
but when i use .net data source configuration wizard for connection, it shows database by using both server or alias.
But that connection string when i use in code it gives me above sql server error 40 , native connection….. .
when enter sqlcmd on command propmt it also gives me same kind of error.
please note that there is no LAN driver on my system.
Please help me ,
Thanks in advance
I have followed the steps demonstrated in this article but I have yet to find where the problem lays with my situation.
Here is the error I am getting:
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)
Perhaps it is addressed here but being a novice with this kind of stuff I haven’t seen it.
Thank you if you can shine a light on this problem.
hi
i m using visual stdio 2010.
when i create new sql server database in vs2010 ,it asks for server name and
database name (new).it gives an error like “Login failed for user ‘server_name\User’. (Microsoft SQL Server, Error: 18456)”
I was getting neumerous errors after migrating to a new SQL cluster. after about a month of troublshooting, I decided to try to update my network card drivers on the new SQL cluster. this fixed all the SQL errors for me.
hi
i have the same problem what you are discuss here when i used aspnet_regserv ,and tried many thing to get ride of it ,nothing helped me actually the error was a small mistake from me i used server name as user-pc
instead of user-pc/SQLEXPRESS
:)
pls give reply to this error
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: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server)