# Region and version availability
<a name="oracle-kerberos-setting-up.RegionVersionAvailability"></a>

Feature availability and support varies across specific versions of each database engine, and across Amazon Web Services Regions. For more information on version and Region availability of RDS for Oracle with Kerberos authentication, see [Supported Regions and DB engines for Kerberos authentication in Amazon RDS](Concepts.RDS_Fea_Regions_DB-eng.Feature.KerberosAuthentication.md).

**Note**  
Kerberos authentication isn't supported for DB instance classes that are deprecated for RDS for Oracle DB instances. For more information, see [RDS for Oracle DB instance classes](Oracle.Concepts.InstanceClasses.md).