Because I always forget – Export all SPNs in a domain
To export all the Service Principle Names (SPNs) from a domain use
ldifde -f spns.txt -d DC=resource,DC=domain,DC=local -l serviceprincipalname
LDIFDE queries any available domain controller to retrieve/update AD information.
More information about LDIFDE can be found here
http://support.microsoft.com/kb/555634








