Users Guide

Table Of Contents
418 | VRRP Dell PowerConnect ArubaOS 5.0 | [User Guide
Configuring Master-Local Controller Redundancy
This section outlines the concepts behind a redundancy solution where a master can act as a backup for one or
more local controllers and shows how to configure the Dell controllers for such a redundant solution. In this
solution, the local controllers act as the controller for the APs. When any one of the local controllers becomes
unavailable, the master takes over the APs controlled by that local controller for the time that the local controller
remains unavailable. It is configured such that when the local controller comes back again, it can take control over
the APs once more.
This type of redundant solution is illustrated by the following topology diagram.
Figure 72 Redundant Topology: Master-Local Redundancy
The network in Figure 72, the master controller is connected to the local controllers on VLANs 1 through n
through a Layer-2 network. To configure redundancy as described in the conceptual overview for master-local
redundancy, configure VRRP instances on each of the VLANs between the master and the respective local
controller. The VRRP instance on the local controller is configured with a higher priority to ensure that when
available, the APs always choose the local controller to terminate their tunnels.
z Configure the interface on the master controller to be a trunk port with 1, 2… n being member VLANs.
z Collect the following data before configuring master controller redundancy.
z VLAN IDs on the controllers corresponding to the VLANs 1, 2…n shown in the topology above.
z Virtual IP addresses that has been reserved to be used for the VRRP instances.
z You can use either the WebUI or CLI to configure VRRP on the master controllers (see Table 82). For this
topology, the following are recommended values:
z For priority: Set the local to 110; set the master to 100 (the default value)
z Enable preemption
The following example configuration of the master controller in such a topology for one of the VLANs (in this
case VLAN 22).
Note: This solution requires that the master controller have Layer-2 connectivity to all the local controllers.
Note: The master controller is configured for a number of VRRP instances (equal to the number of local controllers the master is
backing up).