Technical data

BLADE OS 5.1 Application Guide
BMD00136, November 2009 Chapter 14: High Availability
 199
Active-Active Redundancy
In an active-active configuration, shown in Figure 30, two switches provide redundancy for each
other, with both active at the same time. Each switch processes traffic on a different subnet. When a
failure occurs, the remaining switch can process traffic on all subnets.
For a configuration example, see “Active-Active Configuration” on page 202.
Figure 30 Active-Active Redundancy
Virtual Router Group
The virtual router group ties all virtual routers on the switch together as a single entity. As members
of a group, all virtual routers on the switch (and therefore the switch itself), are in either a master or
standby state.
The virtual router group cannot be used for active-active configurations or any other configuration
that require shared interfaces.
A VRRP group has the following characteristics:
 When enabled, all virtual routers behave as one entity, and all group settings override any
individual virtual router settings.
 All individual virtual routers, once the VRRP group is enabled, assume the group’s tracking
and priority.
 When one member of a VRRP group fails, the priority of the group decreases, and the state of
the entire switch changes from Master to Standby.
Each VRRP advertisement can include up to 128 addresses. All virtual routers are advertised within
the same packet, conserving processing and buffering resources.
Internet
Internet
Enterprise
Routing Switch
Switch 1
Switch 2
Servers
Active (subnet A and C)
Active (subnet B and D)