A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible.

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A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible.

haydarkeskin

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Points: 250
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November 19, 2018 at 4:41 am

#378640

Hi,
I've a problem and I need your help. I've an application that connect to SQL server via TCP/IP and connection string contain server IP. Named pipes protocol closed.
Some times the application throw errors like below, than the same connection string write the error on my errorlog table. I can not find where is the problem. Same application run different locations and there is no error. Can you help me?
A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 -The specified network name is no longer available)
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)
A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired)

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RGP SSCarpal Tunnel Points: 4381 More actions · Answer 1

haydarkeskin - Monday, November 19, 2018 4:41 AM
Hi,
I've a problem and I need your help. I've an application that connect to SQL server via TCP/IP and connection string contain server IP. Named pipes protocol closed.
Some times the application throw errors like below, than the same connection string write the error on my errorlog table. I can not find where is the problem. Same application run different locations and there is no error. Can you help me?
A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 -The specified network name is no longer available)
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)
A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired)

1. check if the ports are open (try telnet) from your application server to SQL server - default port 1433.
2. check if you can ping SQL Server from application server.
3. check for firewall rules set on the application server.
4. check if the connection string inside the application code is proper and correct(check the login name etc)
5. SQL Server browser is this enabled and running- in some cases this could also be a reason.
6. Restart SQL server and then give it a try.