User's Manual

571 | Increasing Network Uptime Through
Redundancy and VRRP
Dell Networking W-Series ArubaOS 6.4.x| User Guide
priority, the first controller that comes up becomes the master. However, if you enable VRRP preemption and
all controllers share the same priority, the controller with the highest IP address becomes the master.
The Virtual Router Redundancy Protocol (VRRP) is used to create various redundancy solutions, including pairs
of local controllers acting in an active-active mode or a hot-standby mode, or a master controller backing up a
set of local controllers. The master controller owns the configured virtual IP address for the VRRP instance.
When the master controller becomes unavailable, a backup controller steps in as the master and takes
ownership of the virtual IP address. All network elements (APs and other controllers) can be configured to
access the virtual IP address, thereby providing a transparent redundant solution to your network.
For more information on configuring the VRRP-Based Redundancy, refer to Configuring VRRP Redundancy on
page 579.
High Availability Deployment Models
High availability supports the following deployment modes.
l Active/Active Deployment Model on page 571
l 1:1 Active/Standby Deployment Model on page 571
l N:1 Active/Standby Deployment Model
l Master-Redundancy Deployment Model
The High Availability Fast Failover feature supports APs in campus mode using tunnel, decrypt-tunnel, or bridge
forwarding modes. This feature is not supported on remote APs and mesh APs in any mode.
Active/Active Deployment Model
In this model, two controllers are deployed in dual mode. Controller one acts as standby for the APs served by
controller two, and vice-versa. Each controller in this deployment model supports approximately 50% of its
total AP capacity, so if one controller fails, all the APs served by that controller would fail over to the other
controller , thereby providing high availability redundancy to all APs in the cluster.
Figure 58 Active-Active HA Deployment
1:1 Active/Standby Deployment Model
In this model, the active controller supports up to 100% of its rated capacity of APs, while the other controller
in standby mode is idle. If the active controller fails, all APs served by the active controller would failover to the
standby controller.