Extreme Networks Summit WM3000 Series, Reference Manual

Page: 273 / 513

Summit WM3000 Series Controller System Reference Guide
273
2 Refer to the Configuration field to define the following:
Enable Redundancy
Select this checkbox to enable/disable clustering. Clustering must be
disabled to set a redundancy related parameter. All the modifiable values
are grayed out if enabled
Redundancy
Controller IP
Define the destination IP address used to send heartbeats and update
messages.
Mode
A member can be in either in
Primary
or
Standby
mode. In the
redundancy group, all ‘Active’ members adopt Access Points except the
‘Standby’ members who adopt Access Points only when an ‘Active’
member has failed or sees an access point not adopted by a controller.
Redundancy ID
Define an ID for the cluster group. All the controllers configured in the
cluster should have the same Cluster ID. The valid range is 1-65535.
Discovery Period
Use the
Discovery Period
to configure a cluster member discovery
interval. During the discovery time, a controller discovers the existence of
other controllers within the redundancy group. Configure an interval
between 10 and 60 seconds. The default value is 30 seconds.
Heartbeat Period
The
Heartbeat Period
is the interval heartbeat messages are sent.
Heartbeat messages discover the existence and status of other members
within the group. Configure an interval between
1 and 255 seconds. The default value is 5seconds.
Hold Time
Define the
Hold Time
for a redundancy group. If there are no heartbeats
received from a peer during the hold time, the peer is considered down.
In general, the hold period is configured for three times the heartbeat
period. Meaning, if three consecutive heartbeats are not received from the
peer, the peer is assumed down and unreachable. The hold time is
required to be longer than the heartbeat interval. Configure a hold time
between 10 and 255 seconds. The default is 15 seconds.
Critical Resource
Enter the IP address of the critical resource. When the heartbeat is lost,
this resource will be checked for reachability. The critical resource can be
any gateway, server or host. If the critical resource is not reachable and
the heartbeat is still lost, the controller will deadopt APs and continue to
deadopt APs until instructed otherwise.
Handle STP
convergence
Select the
Handle STP convergence
checkbox to enable
Spanning Tree
Protocol
(STP) convergence for the controller. In general, this protocol is
enabled in layer 2 networks to prevent network looping. If the network is
enabled for STP to prevent looping, the network forwards data only after
STP convergence. Enabling STP convergence delays the redundancy state
machine execution until the STP convergence is completed (the standard
protocol value for STP convergence is 50 seconds). Delaying the state
machine is important to load balance Access Points at startup.
Enable DHCP
Redundancy
Enables DHCP Redundancy for member controllers. DHCP Redundancy
allows an administrator to have only one DHCP server running at any time
in a cluster. The clustering protocol enables all peers participating in
DHCP redundancy to determine the active DHCP server among them. The
controller with lowest Redundancy IP is selected as the active DHCP
server for the cluster. This selected active DHCP server can be either a
primary or standby controller. The other controllers do not provide DHCP
service as long as the selected DHCP server controller is active.