【文章內(nèi)容簡介】 rewall exists between the client puter and the puter that is running SQL Server, make sure that the ports that are required to municate through the firewall are you use the TCP/IP protocol to connect to the instance of SQL Server, make sure that you can use the Tel program to connect to the port where SQL Server is listening. To use the Tel program, run the following mand at a mand prompt: Tel IP Address Port NumberIf the Tel program is not successful and you receive an error message, resolve the error and then try to connect Because of issues that were caused by the Slammer virus, the User Datagram Protocol (UDP) port 1434 may be blocked on your authentication and security issuesConnections to SQL Server may not be successful because of authentication failures. If the authentication fails, you may receive one of the following error messages:Login failed for user 39。username39。Login failed for user 39。NTAUTHORITY\ANONYMOUS LOGON39。Login failed for user 39。null39。 If you receive an error message because of an authentication failure and the error message does not mention a specific SQL Server login name, troubleshoot the problem with Windows authentication. You may receive the following error message because of problems with Windows authentication: Cannot generate SSPI ContextThe following problems may cause authentication and security issues: ? Problems occur with NTLM authentication or with Kerberos authentication.? The domain controller cannot be contacted because of connectivity issues.? Problems occur with trust relationships across domains. For more information about possible causes, see the event logs on the puter. To work around connectivity problems with Windows authentication, you can use SQL Server Authentication to connect to the instance of SQL Server. If the connection is not successful when you use SQL Server Authentication, you receive the following error message: Login failed for user 39。username39。 . Not associated with a trusted connectionTo troubleshoot this problem, follow these steps. Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk. 1. Make sure that the instance of SQL Server is configured to use Windows authentication and SQL Server Authentication. To do so, make sure that the following registry keys are on the puter that is running SQL Server. For the d Server:HKEY_LOCAL_MACHINE\Software\Microsoft\MSSQLServer\MSSQLServer\LoginModeFor the named instance of SQL Server: HKEY_LOCAL_MACHINE\Software\Microsoft\MicrosoftSQLServer\InstanceName\MSSQLServer\LoginModeMake sure that the following registry key values are set:Authentication type ValueWindows authentication only 1Mixed mode (SQL Server Authentication and Windows authentication) 2Note If you make any changes to the registry, you must stop and then 大連交通大學(xué)信息工程 學(xué)院 2021 屆本科生畢業(yè)設(shè)計(jì)（論文）外文翻譯 9 restart the instance of SQL Server for the changes to take . Try to connect to the instance of SQL Server by using different Windows accounts or SQL Server login accounts. This can help determine if the connection is not successful because of problems with a particular login account. For example, the password of the login account may have been . Try to connect to the instance of SQL Server by using different protocols. For example, the connections that use the TCP/IP protocol with Windows authentication may not be successful, but connections that use the named pipes protocol with Windows authentication may be successful. If you are using certificates, you may receive a Secure Sockets Layer (SSL) security error message when you try to connect to the instance of SQL Server. Troubleshoot stress on TCP/IP sockets When you use the SQL Server ODBC driver, the Microsoft OLE DB Provider for SQL Server, or the managed provider, you can disable connection pooling by using the appropriate application programming interfaces (APIs). When you disable connection pooling and your application frequently opens and closes connections, the stress on the underlying SQL Server work library may increase. Sometimes, the Web servers and the JDBC drivers may also try to connect to the instance of SQL Server. Therefore, the increase in connection requests to SQL Server may be more than SQL Server can handle. This may stress the TCP/IP sockets, and you may receive the following error message in the SQL Server error log file: 20210807 20:46: server Error: 17832, Severity: 20, State: 6 20210807 20:46: server Connection opened but invalid login packet(s) sent. Connection additional information, click the following article numbers to view the articles in the Microsoft Knowledge Base: 154628 INF: SQL logs 17832 with multiple TCP\IP connection requests 328476 TCP/IP settings for SQL Server drivers when pooling is disabled Note You may not notice the stress on TCP/IP sockets if you are running SQL Server 2021 SP3 or SQL Server 2021 SP3a because a limit on the number of login packets was added. The 17832 error occurs when you use thirdparty drivers to connect to the instance of SQL Server. To resolve this problem, contact the thirdparty vendor and obtain drivers that have been tested to work with SQL Server 2021 SP3 and SQL Server 2021 if the instance of SQL Server is started in singleuser mode If the instance of SQL Server that you are trying to connect to is started in singleuser mode, only one connection can be established with SQL Server. If you have software running on your puter that automatically connects to SQL Server, the software can easily use the only connection. For example, the following software can automatically connect to the instance of SQL Server:? SQL Server A