Cisco ASA Series User Manual

CHAPTER
1-1
Cisco ASA Series CLI Configuration Guide
1
Configuring Active/Standby Failover
This chapter describes how to configure Active/Standby failover and includes the following sections:
• Information About Active/Standby Failover, page 1-1
• Licensing Requirements for Active/Standby Failover, page 1-6
• Prerequisites for Active/Standby Failover, page 1-6
• Guidelines and Limitations, page 1-6
• Configuring Active/Standby Failover, page 1-7
• Controlling Failover, page 1-16
• Monitoring Active/Standby Failover, page 1-18
• Feature History for Active/Standby Failover, page 1-18
Information About Active/Standby Failover
This section describes Active/Standby failover and includes the following topics:
• Active/Standby Failover Overview, page 1-1
• Primary/Secondary Status and Active/Standby Status, page 1-2
• Device Initialization and Configuration Synchronization, page 1-2
• Command Replication, page 1-3
• Failover Triggers, page 1-4
• Failover Actions, page 1-5
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 IP addresses 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.

Cisco ASA Series Specifications

General

Model	ASA 5505
Interfaces	Varies by model (Fast Ethernet, Gigabit Ethernet, 10 Gigabit Ethernet, etc.)
High Availability	Active/Standby or Active/Active (varies by model)
Power Supply	Varies by model
Form Factor	Varies by model
Operating System	Cisco ASA Software
IPsec VPN	Supported
SSL VPN	Supported
IPS Throughput	Varies by model