A service principal name (SPN) is a unique identifier of a service instance. SPNs are used by Kerberos authentication to associate a service instance with a service logon account. This allows a client application to request that the service authenticate an account even if the client does not have the account name.
If you install multiple instances of a service on computers throughout a forest, each instance must have its own SPN. A given service instance can have multiple SPNs if there are multiple names that clients might use for authentication. For example, an SPN always includes the name of the host computer on which the service instance is running, so a service instance might register an SPN for each name or alias of its host. For more information about SPN format and composing a unique SPN,
https://docs.microsoft.com/en-us/windows/win32/ad/service-principal-names
Named instance
- MSSQLSvc/<FQDN>:[<port> | <instancename>], where:
- MSSQLSvc is the service that is being registered.
- <FQDN> is the fully qualified domain name of the server.
- <port> is the TCP port number.
- <instancename> is the name of the SQL Server instance.
Default instance
- MSSQLSvc/<FQDN>:<port> | MSSQLSvc/<FQDN>, where:
- MSSQLSvc is the service that is being registered.
- <FQDN> is the fully qualified domain name of the server.
- <port> is the TCP port number.
—>> SPN setting for SQL Server connection problem
To List SPN we need -L parameter.
SetSPN -L domain\account
--->> SPN setting for SQL Server connection problem To List SPN we need -L parameter. SetSPN -L domain\account To create/add SPN we need to use -A parameter SetSPN –A MSSQLSvc/<SQL Server FQDN>:<port> <Domain\Account>
Microsoft Kerberos Configuration Manager for SQL Server is a diagnostic tool that helps troubleshoot Kerberos related connectivity issues with SQL Server, SQL Server Reporting Services, and SQL Server Analysis Services.
Download Tool
https://www.microsoft.com/en-ca/download/details.aspx?id=39046
