Cannot establish connection to SQL Server - sql-server

I am trying to access SQL DB that is located on my computer from an application that is located on a server (has IIS7).
I set the ConnectionString in the WebConfig with the IP of my computer and I always get 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)
I wanted to enable remote connections as it was mentioned in the error. These are the things that I tried in order to make it work:
Made sure that "Allow remote connections" to this server is checked in the properties window of my server
Enabled TCP/IP in the SQL Server Configuration Manager
Right clicking on the TCP/IP and in "Properties" set the port to 1433 and removed the "0" in the Dynamic Ports
Created a new rule in the Windows Firewall to allow the connection from port 1433
Added sqlservr.exe from the MSSQL/Binn folder to "Allow a program through Windows Firewall"
Restarted the service
None of it helped. What else can I do?
EDIT:
Connection string:
<connectionStrings>
<add name="someName" connectionString="Database=someDB;Server=<my computer's IP>;User=userName;Password=123" providerName="System.Data.SqlClient"/>
</connectionStrings>

I am showing SQL Express setting this should be same in standard and other versions.
check this and follow the first link for connection specification and testing for this problem.
Check these links for checking error exists regarding this particular topic and fixing this:
Resolving “A network-related or instance-specific error"
SQLAuthority- could not open connection

Related

Connect IIS in DMZ to SQL Server on intranet

I'm trying to connect IIS which is running on a server in the DMZ to a SQL Server instance on the company intranet. But, I'm getting the following error:
An unhandled exception occurred while processing the request.
Win32Exception: Access is denied.
Unknown location
SqlException: 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)
Do I need specific ports opened up on one of the servers? Or is there something else I need to do?
Considering your SQL server is running, start with the networking. On which port is your SQL instance listening (default 1433)?
If you don't know, open the SQL Server Configuration Manager (on the SQL Server). Navigate to the SQL Server Network Configuration > Protocols for %instancename% > TCP/IP > IP Addresses. Then, test if something is blocking this connection; on your IIS in PowerShell:
Test-NetConnection -ComputerName sqlservername -Port 1433
If this doesn't work, check the Inbound Rules for Windows Firewall on your SQL Server. Make sure you work on the right network profile and eventually speak to the one managing your network systems in your company.
Maybe your IIS can't resolve the SQL Servers hostname? Try using the IP and check your DNS configuration.
There might also be something off with your connection string. Mind posting it here?

IIS can't connect to SQL Server, but an external PC can

My VB.Net code connects to SQL Server. On my PC, it succeeds. On IIS running on the same machine as SQL Server, it fails. Any ideas?
I've tested:
I've tried IP address and server name. Same result.
I've tried Integrated Security and I've tried username/password. Same result.
On the server machine, Excel and SSMS can connect to SQL server using the same server name, username and password.
The fact that my PC can connect excludes many common problems including: ip address, server name, port, firewall, turn on sql server, connection string, credentials, permissions, sql roles.
Server (IIS and SQL) info: VB.Net, connection string providerName="System.Data.SqlClient", Windows Server 2008 SP2.
My PC info: Run website in Visual Studio 2019. Connects to same DB using same connection string (not local db and not as a different user).
Code (fails on second line):
oConn = ConnectionService.DatabaseName.Connect
oConn.Open()
Connection string: connectionString="Data Source=IP Address\SQLEXPRESS;Initial Catalog=DatabaseName;Integrated Security=False;Persist Security Info=False;User ID=Username;Password=Password;" providerName="System.Data.SqlClient"
Error message: System.Data.SqlClient.SqlException (0x80131904): 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) ---> System.ComponentModel.Win32Exception (0x80004005): The network path was not found
Oops. Right after posting this, I found out Web.Config pointed to a different connection string. That should explain and solve everything. I had checked Web.Config, but it turns out that that wasn't the one this server was using.

provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified No fix?

I recently added a second site to my server. That site gives me the dreaded:
System.Data.SqlClient.SqlException: 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 have no idea why I am getting this. I've gone through this and this to no avail. This is a new MVC4 application I have at beta.vinformative.com in IIS 7. The other site is a MVC3 site at vinformative.com. It is running fine. Both of their databases have the exact same connection string and they are both on the same SQL server. I've given the same user mapping and role membership for NT Authority\Network Service to both databases.
Here is what I've tried so far:
MSSQLSERVER SQL Server service is running along with SQL Server Browser, and SQL Server Agent
I've added a firewall inbound rule for SQL Server browser
Made sure TCP/IP is enabled in sql server configuration
Added port 1433 TCP to the firewall
Enabled remote connection to db server
Successfully pinged the machine
Used portqry to see the db server on UDP 1434
I can connect to the site locally when I am remotely logged into my server. Furthermore, I have an ELMAH instance in the application for error logging and that is updating the database correctly. I feel like I am taking crazy pills because this should be working and I can't find an outright error. Please help!
Here is my connection string
<add name="vfContext" connectionString="Data Source=vinformative;Initial Catalog=vf3;Integrated Security=True" providerName="System.Data.SqlClient" />
Could be EF - see here.
Also, remote access cannot work with "Integrated Security=True" as far as I know, should use "User ID=******;Password=****;Integrated Security=False".

Cannot establish a connection to the server

I just fixed my computer here and there after I was facing some BSOD's and when I now try to open up SQL Server using Windows Authentication, displays the following message and doesn't login.
TITLE: Connect to Server
Cannot connect to SARIN-PC\SQLEXPRESS.
ADDITIONAL INFORMATION:
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) (Microsoft
SQL Server, Error: -1)
I checked in the Configuration Manager, Named Pipes, Shared Memory and TCP/IP all are enabled. What went wrong now? :-|
Did you check SQL Server Configuration Manager->SQL Service(MSSQL). Is it runnig?
You also can check:
SQL Service(MSSQL)->Properties->Service->Host Name is eqals to "Service Name"
which you must enter when you start your MSSQL Manadgment Studio.
If it don`t help you can read this articlea http://blogs.msdn.com/b/sql_protocols/archive/2007/05/13/sql-network-interfaces-error-26-error-locating-server-instance-specified.aspx
Check if you are typing in the right computer name and instance name. The error basically points to that.

Remote login to SQL Server Express 2008

I am remotely accessing SQL Server Express 2008.
I have turned on service "SQL Server Browser"
I have turned on service "SQL Server (SQLExpress)"
I have enabled TCP/IP and set dynamic ports to blank and tcp port to 1433 in properties
I can connect localy(using ip) so my credentials are correct.
I have a exceptions record in my windows firewall setting port 1433 as open.
I have performed a system reboot making all services are still turned on.
After i try and connect via a remote computer I get this error.
Cannot connect to XXX.XXX.XXX.XX
===================================
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) (.Net SqlClient Data Provider)
------------------------------
Error Number: 3
Severity: 20
State: 0
your ideas and solutions will be greatly appreciated.
KJ
Edit
Hi and thanks for the quick responses. At present there is no connection string. I am trying to connect using: SQL Server Management Studio 2008
Edit 2
Hey Nick.
I am connecting using SERVERNAME\SQLEXPRESS I turned off windows firewall off and still there was no joy.
I tried adding the port like you suggested:
===================================
Cannot connect to XXX.XXX.XXX.XX, 1433.
===================================
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.) (.Net SqlClient Data Provider)`
please show us the connection string in you are using to connect to the server with.
If your connecting using the instance name. eg. SERVERNAME\SQLEXPRESS then you will need to open up your firewall for the SQL Browser service i.e. UDP port 1434.
Alternatively, try using the port in your connection string and forget the instance name. Eg. in SSMS you can connect using SERVERNAME,1433 where 1433 is the port you've specified sql server listens to.
You say you have configured TCP/IP but your connection error message says this:
provider: Named Pipes Provider
Update
It appears you have one protocol enabled on Sql Express and are trying to connect with another via Sql management Studio. You need to connect with the TCP provider or enable Named Pipes on your Sql Server Express Configuration.
To connect with TCP, in Sql Management Studio click the Options button on the login page. This will take you to a Connection Properties page where you can select the provider. The Network protocol is probably set to default or Named Pipes at the moment and it needs to be changed to TCP.
Alternatively, in Sql Server Configuration Manager, enable Named Pipes in Protocols for Sql Express.

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