Redundancy
The Cisco Secure PIX 515 series and above and the Cisco ASA Security Appliance can be
configured in pairs with a primary system and a hot standby. This redundancy and stateful
failover make the Cisco Security Appliance family of firewalls a high-availability solution for
use in protecting critical network segments. If the primary firewall fails, the secondary
automatically assumes the load, dramatically reducing the chances of a network outage.
Failover is discussed in greater detail in Chapter 12, “Cisco Security Appliance Failover.”