System Center Configuration Manager Team Blog : Known Issue: Supernets in Active Directory Sites Used as Site Boundaries
We have recently updated the Configuration Manager Documentation Library regarding site boundary configurations. This change was made to clarify the use of supernets, which remain unsupported but have been a source of confusion resulting in support calls. The confusion comes when an Active Directory site is configured as a boundary and that Active Directory site contains one or more supernets.
System Center Configuration Manager Team Blog : Known Issue: Supernets in Active Directory Sites Used as Site Boundaries