Explanation
Auto-site clustering is a feature that allows gateways in the same site and group to form a cluster automatically. However, this mode does not support VRRP IP addresses, which are required for dynamic authorization (CoA) from ClearPass Policy Manager (CPPM) to the gateways. Dynamic authorization is a mechanism that allows CPPM to change the attributes or status of a client session on the gateways without requiring re-authentication. This is useful for applying policies, roles, or bandwidth limits based on various conditions. Without VRRP IP addresses, CPPM would not be able to send CoA messages to the correct gateway in case of a failover event, resulting in inconsistent or incorrect client behavior.
To enable VRRP IP addresses for dynamic authorization, you need to set up gateway clusters manually and assign a VRRP VLAN and a VRRP IP address to each cluster. This way, CPPM can use the VRRP IP address as the NAS IP address for RADIUS communications and CoA messages. The VRRP IP address will remain the same even if the active gateway in the cluster changes due to a failover event, ensuring seamless operations. You can find more information about how to set up gateway clusters manually and configure VRRP IP addresses in the Gateway Cluster Deployment - Aruba page and the ClearPass Policy Manager User Guide1.