Concept Guide
393| ha Dell Networking W-Series ArubaOS 6.5.x| Reference Guide
Parameter
Description
heartbeat
The high availability inter-controller heartbeat feature allows for faster AP
failover from an active controller to a standby controller, especially in situ-
ations where the active controller reboots or loses connectivity to the net-
work.
heartbeat-interval
<heartbeat-interval>
Enter a heartbeat interval in the Heartbeat Interval field to define how
often inter-controller heartbeats are sent.
Range: 100-1000 ms; Default:100ms
heartbeat-threshold
<heartbeat-threshold>
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
no
Negates or removes any configured parameter.
over-subscription
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 Seriescontroller 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.
pre-shared-key <key>
Define a pre-shared key to be used with the state synchronization
feature.
preemption
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 ori-
ginal active controller once that controller is reachable again. When you
enable this setting, the AP will wait for the time specified by the lms-hold-
down-period parameter in the ap system-profile profile before the standby
AP attempts to switch back to original controller.
state-sync
State synchronization improves failover performance by synchronizing
PMK and Key cache values from the active controller to the standby con-
troller, 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 pre-
shared 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