User's Guide

Table Of Contents
hwc_fastfailover.fm
Availability and session availability
Availability
9034530-02,
March 2010
HiPath Wireless Controller, Access Points and Convergence Software V7.11, User Guide 383
All mobile user’s sessions using the failover Wireless AP will terminate except
those associated to a Bridge traffic locally at the AP and if the Maintain client
sessions in event of poll failure option is enabled on the AP Properties tab or
AP Default Settings screen.
When the Wireless APs connect to the second HiPath Wireless Controller, they
are either assigned to the VNS that is defined in the system’s default AP
configuration or manually configured by the administrator. The mobile users log
on again and are authenticated on the second HiPath Wireless Controller.
When the failed HiPath Wireless Controller recovers, each HiPath Wireless
Controller in the pair goes back to normal mode. They exchange information
including the latest lists of registered Wireless APs. The administrator must
release the Wireless APs manually on the second HiPath Wireless Controller, so
that they may re-register with their home HiPath Wireless Controller. Foreign APs
can now all be released at once by using the Foreign button on the Access
Approval screen to select all foreign APs, and then clicking Release.
To support the availability feature during a failover event, administrators need to
do the following:
1. Monitor the critical messages for the failover mode message, in the
information log of the remaining HiPath Wireless Controller (in the Logs &
Traces section of the HiPath Wireless Assistant).
2. After recovery, on the HiPath Wireless Controller that did not fail, select the
foreign Wireless APs, and then click Release on the Access Approval
screen.
7.1.2 Availability prerequisites
Before you configure availability, ensure you have completed the following:
Choose the primary and secondary HiPath Wireless Controllers.
Verify the network accessibility for the UDP connection between the two
controllers. The availability link is established as a UDP session on port
13911.
Set up a DHCP server for AP subnets to support Option 78 for SLP, so that it
points to the IP addresses of the physical interfaces on both the HiPath
Wireless Controllers.
Ensure that the Poll Timeout value on the AP Properties tab Advanced
dialog is set to 1.5 to 2 times of Detect link failure value on the HiPath
Wireless Controller > Availability screen. For more information, see
Section 4.4.2, “Configuring a Wireless AP’s properties”, on page 122.