I have two web servers that each run an identical ASP application. These web servers connect to the same SQL server. One of the servers is running the application fine, but the other is throwing the following 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: SQL Network Interfaces, error: 28 - Server doesn't support requested protocol)
I did a wireshark capture on both of traffic in between the web server and the sql server. On the working server, the traffic is using TCP. On the nonworking server, I see alot of UDP traffic, which SQL server doesn't support (makes sense given the error message). Where is the protocol used determined? The applications on each server are identical, so it can't be an application level config issue. I am not a network guy so I am at a loss
Thanks,
Joseph
You can set the "network protocol" in the connection string.
It's worth a try.
Connect via an IP address
Data Source=190.190.200.100,1433;Network Library=DBMSSOCN;
That connection string is not complete, I'm showing the relevant portions.
That sample comes from
http://www.connectionstrings.com/sql-server-2008
This article is old, but will explain the Network Library options.
http://support.microsoft.com/kb/238949
The 2 most common (in my experience) are:
dbnmpntw - Win32 Named Pipes
dbmssocn - Win32 Winsock TCP/IP
EDIT
The other trick is to install PortQryUI, and place this small utility on the "client" machine.......and "poke" the Sql Server, and make sure you get the same results.
http://www.microsoft.com/en-us/download/details.aspx?id=24009
This will help identify any firewall issues...OUTSIDE of using sql server clients.
Related
Dear stackoverflow community,
I have a problem using Direct Query connect in Power BI. I have an SQL Express server running on a remote server with a Linux operating system. I connect to this server using a VPN. I can connect to this SQL server with my local MS SQL Express installation no problem. I can also import the data to my local Power BI desktop installation using Get Data>SQL Server>Import.
However when I try to use Direct Query, it fails after executing for a while and setting up the Direct Query connections. I receive the following Error Message:
"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);The network path was not found. The exception was raised by
the IDbConnection interface."
It's also interesting that it appears like something is loading in the fields pane
I feel it could be a problem with allowing remote connections in the Linux remote MS SQL Express Server, but have found no way of allowing this in Linux. On my Windows installation it's no problem.
I'm really excited to solve this issue and start building my dashboard. But I need a live connection for that...
Thank you for your time reading this and your replies in advance.
This was solved by using the 64 bit version Power BI from the microsoft store and not adding the portnumber when making the sql connection. I recommend admins not to delete this as finding this solution wasn't too straightforward.
I have an app service with hybrid connection enabled(on a VM in the same network with the SQL Sever) for me to access on prem SQL Server, which I don't own. However, the connectivity has been pretty unstable.
I am able to access to the SQL Server probably for maybe 5% of the tries and mostly I just get error
One or more errors occurred. (A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.
I'm able to log in thru SSMS on the VM. Connection string should be alright since I can access locally(local network is the same network as the SQL Server).
Named instances use dynamic ports and UDP, which are not supported by Hybrid Connections. Suggest you using static port as Nick mentioned. Please refer to this document Connect to on-premises SQL Server from a web app in Azure App Service using Hybrid Connections to get more information.
provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.
What is your Windows version? When Windows versions that don't contain the leading zero fixes for TLS_DHE will display this error message. You can try to update windows version or disable the TLS_DHE ciphers to solve this issue. Please refer to this document.
Yesterday I had no problems. Now when any client (even MSSMS from a client machine) tries to access sql server located on a server in the domain I get the following error: TITLE: Connect to Server
Cannot connect to SERVER\Instance
A network-related or instance-specific error occurred while establishing a connection to SQL Server. ...
SQL server is 2014 on a Windows 2012 R2 Server which also hosts the Active Directory.
I can connect using MSSMS from the server itself to the database. The log states that the service started and is listening on port 63782. I can also connect to sql server from the host machine using ip:port (192.168.0.2, 63782). But I cannot connect to it this way from the clients. (I made no changes to the firewall and the rule for lan-lan is allow all services and all connections).
Shared Memory, TCP/IP and Named Pipes are enabled on the sql server configuration Manager.
I can ping to the server from the clients and to the clients from the server.
The main difference between yesterday and today is that I had to reinstall the DNS on the server. The DNS appears to be working very well and I can't find any DNS errors on the server. I don't think its the firewall but I added two rules that allow UDP and TCP specifically within the local network (even though there is a policy which allows all traffic within the local network).
I am at a loss and would appreciate some assistance into solving the problem or even where to look.
I have an ASP.NET Core 1.1 Web API which runs in a Docker container on Ubuntu and connects out to a SQL Server database (SQL Server 2012 SP3) on a Windows server. This works in 3 out of 4 of out environments, but in one environment it cannot connect to the SQL Server and I am trying to troubleshoot it.
The error is:
Unhandled Exception: 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: TCP Provider, error: 25 - Connection string is not valid)
The SQL Server has an instance name: SQLSERVER1\APPS. From the Linux server I can ping the server SQLSERVER1 and telnet to SQLSERVER1 1372 (1372 is the port for the APPS instance: so network connectivity is there.
The only space I can see for the problem to occur is how .NET Core translates the instance name to a port number. Does anyone know how this is done and whether it is configurable on the client machine?
Remote named instance listening port discovery relies SQL Server Browser Service and protocol. As you cannot leverage this for your Linux docker image, I suggest you connect by explicitly specifying the port and omitting the instance name: "server=tcp:SQLSERVER1,1372;database=...;...":
The name or network address of the instance of SQL Server to which to connect. The port number can be specified after the server name: server=tcp:servername, portnumber
BTW if you live the instance name it should make no difference whatsoever after you explicitly specify the port.
PS. After reading again the question, the issue is related but different cause. Normally the Linux container can discover the Windows SQL Server, as the Browser service is probably up and running (proof that 3 envs. it works). In the 4th environment it means something blocks the discovery. Either the Browser service is stopped, or the browser discovery protocol listening port is blocked in the FW (UDP 1433), or perhaps the UDP packet (or the response!) is lost somewhere between the container and the server. You can investigate and find the root cause, but, you can also just ignore the problem and work around the issue by... specifying the port explicitly, just as I showed.
I have installed SQL Server 2005 in mixed mode.
I am able to connect to Database "locally" i.e.
(Server-name/Instance or internal-ip/Instance) using both kinds of Authentication.
I have configured SQL Server for remote connection by following below steps
Steps:
Enable remote connections on the instance of SQL Server that you want to connect to from a remote computer.
Turn on the SQL Server Browser service.
Configure the firewall to allow network traffic that is related to SQL Server and to the SQL Server Browser service. Ref: http://support.microsoft.com/kb/914277#method3
In addition, I have turned off my firewall.
I am able to ping my computer through the External IP.
But when it comes to connecting to sql server, its giving the error.
"TITLE: Connect to Server
Cannot connect to <ip address>\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)
For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=-1&LinkId=20476
Please help me,
I have referred many article and tested all possible solution, but nothing seems to be working for me.
It turned out to be an issue with Port Forwarding from my Modem/Router to respective Machine IP.
To resolve this issue, I just configured my Router so that it can accept the request on some specific port [External IP:port_number] and then map that request to my machine's [Internal IP:port_number] as multiple computers were connected to a single router.
Also, please make sure that Firewall on your server is configured correctly to accept the inbound network traffic on that specific port.