Extreme Networks Summit WM User Manual page 244

Availability and session availability
4 Select the Enable Fast Failover checkbox.
5 Type the appropriate value in Detect link failure box.
The Detect link failure field specifies the time period within which the system detects the link
failure after the link has failed. For fast failover configuration, this parameter is tied closely to the
Poll Timeout parameter on the WAP Registration page. The Poll Timeout field specifies the time
period for which the Altitude AP waits before re-attempting to establish a link when its polling to
the primary Summit WM Controller fails.
For the fast failover feature to work within the time frame of 5 seconds, the Poll Timeout value
should be 1.5 to 2 times of Detect link failure value. For example, if you have set the Detect link
failure value to 2 seconds, the Poll Timeout value should be set to 3 or 4 seconds.
244
Summit WM User Guide, Software Version 5.3