Multiple SPNs per instance?

Question

Multiple Instance, Multiple Statically Assigned ports 'per' instance.  eg;
Instance1 - ports 15000, 15001, 15002
Instance2 - ports 16000, 16001, 16002
Port 15000 - DatabaseA
Port 15002 - DatabaseB
Port 15002 - DatabaseC
Port 16000 - DatabaseD
Port 16001 - DatabaseE
Port 16002 - DatabaseF
Each 'instance' uses a different Domain User account.
Does each port need to be registered with a server principle name?  Or is just one ok?  Ie:
Instance1:
setspn -A MSSQLSvc/myhost.redmond.microsoft.com:15000 microsoft\domainaccountname1
setspn -A MSSQLSvc/myhost.redmond.microsoft.com:15001 microsoft\domainaccountname1
setspn -A MSSQLSvc/myhost.redmond.microsoft.com:15002 microsoft\domainaccountname1
Instance2:
setspn -A MSSQLSvc/myhost.redmond.microsoft.com:16000 microsoft\domainaccountname2
setspn -A MSSQLSvc/myhost.redmond.microsoft.com:16001 microsoft\domainaccountname2
setspn -A MSSQLSvc/myhost.redmond.microsoft.com:16002 microsoft\domainaccountname2

Answer 1

Hi,
I think you need to registry the SPN with the each different port numbers that was used by the SQL Server instance.
Per
http://msdn.microsoft.com/en-us/library/ms677949(v=vs.85).aspx
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.
Note: an SPN must be unique in the forest in which it is registered. If it is not unique, authentication will fail.
Reference:
How to Configure an SPN for SQL Server Site Database Servers
http://technet.microsoft.com/en-us/library/bb735885.aspx
Thanks.
Tracy Cai
TechNet Community Support