Dell W-Series 304 Instant 6.5.1.0-4.3.1.0 CLI Reference Guide - Page 393

Parameter heartbeat heartbeat-interval heartbeat-threshold no over-subscription pre-shared-key preemption state-sync Description The high availability inter-controller heartbeat feature allows for faster AP failover from an active controller to a standby controller, especially in situations where the active controller reboots or loses connectivity to the network. Enter a heartbeat interval in the Heartbeat Interval field to define how often inter-controller heartbeats are sent. Range: 100-1000 ms; Default:100ms Enter a heartbeat threshold in the Heartbeat Threshold field to define the number of heartbeats that must be missed before the APs are forced to fail over to the standby controller. Range: 3-10 heartbeats; Default: 5 heartbeats Negates or removes any configured parameter. The standby controller oversubscription feature allows a standby controller to support connections to standby APs beyond the controller's original rated AP capacity. Starting with ArubaOS 6.4.0.0, a W-7200 Series controller acting as a standby controller can oversubscribe to standby APs by up to four times that controller's rated AP capacity, as long as the tunnels consumed the standby APs do not exceed the maximum tunnel capacity for that standby controller. Define a pre-shared key to be used with the state synchronization feature. If you include this optional parameter to enable preemption, an AP that has failed over to a standby controller attempts to connect back to its original active controller once that controller is reachable again. When you enable this setting, the AP will wait for the time specified by the lms-holddown-period parameter in the ap system-profile profile before the standby AP attempts to switch back to original controller. State synchronization improves failover performance by synchronizing PMK and Key cache values from the active controller to the standby controller, allowing clients to authenticate on the standby controller without repeating the complete 802.1X authentication process. NOTE: To use the state synchronization feature, configure a preshared key with the pre-shared-key parameter. Usage Guidelines The High Availability:Fast Failover feature supports redundancy models with an active controller pair, or an active/standby deployment model with one backup controller supporting one or more active controllers. Each of these clusters of active and backup controllers comprises a high-availability group. Note that all active and backup controllers within a single high-availability group must be deployed in a single master-local topology. The High Availability: Fast Failover features works across Layer-3 networks, so there is no need for a direct Layer-2 connection between controllers in a high-availability group. By default, an AP's active controller is the controller to which the AP first connects when it comes up. Other dual mode or standby mode controllers in the same High Availability group become potential standby 393| ha Dell Networking W-Series ArubaOS 6.5.x | Reference Guide