What is an SPN and why Should I use an SPN in Windows?

A Service Principal Name (SPN) is a unique name identifier for a service instance. Similarly, think of an SPN like a DNS CNAME record. An SPN is a pointer to a domain account. It is an identifier to get to a listening process. For example:

 

COOL/Service1 is an alias for domain account RBAC.LOC\MyAccount

COOL/Service2 is also an alias for domain account RBAC.LOC\MyAccount

And so on..

 

An SPN Format is: Service Name / Host Name: Port Number

The actual SPN’s are stored in Active Directory servicePrincipalName attribute

 

 

An example of an SPN service.

            Service Name = SQLSERVICE1

            Host Name = SQLSERVER.SOLUTION.COM

            Port Number = 2001

 

 

To add an account to the SPN: setspn -s servername/MSSQL:port number domain/account

 

Full List of Windows SPN Commands: