CHAPT ER
62-1
Cisco ASA 5500 Series Configuration Guide using the CLI
62
Configuring Active/Standby Failover
This chapter describes how to configure Active/Standby failover and includes the following sections:
Information About Active/Standby Failover, page62-1
Licensing Requirements for Active/Standby Failover, page62-6
Prerequisites for Active/Standby Failover, pag e 62-6
Guidelines and Limitations, page62-6
Configuring Active/Standby Failover, page62-7
Controlling Failover, page62-16
Monitoring Active/Standby Failover, page62-18
Feature History for Active/Standby Failover, page62-18

Information About Active/Standby Failover

This section describes Active/Standby failover and includes the following topics:
Active/Standby Failover Overview, page62-1
Primary/Secondary Status and Active/Standby Status, page62-2
Device Initialization and Configuration Synchronization, page62-2
Command Replication, page62-3
Failover Triggers, page62-4
Failover Actions, page 62-4

Active/Standby Failover Overview

Active/Standby failover enables you to use a standby ASA to take over the functionality of a failed unit.
When the active unit fails, it changes to the standby state while the standby unit changes to the active
state. The unit that becomes active assumes the IP addresses (or, for transparent firewall, the
management IP address) and MAC addresses of the failed unit and begins passing traffic. The unit that
is now in standby state takes over the standby IPaddresses and MAC addresses. Because network
devices see no change in the MAC to IP address pairing, no ARP entries change or time out anywhere
on the network.