Cisco ASA 5500 Active/Standby – Zero Downtime Upgrade
KB ID 0000733 Problem You have two ASA firewalls deployed in Active/Standby failover configuration, and need to upgrade either the operating system or the ASDM. As you already have a high availability solution you do not want any downtime. Before we start, we need to make sure we know the difference between primary, secondary, active and standby. From the rear (Active=Green, Standby=Amber) The Primary and Secondary firewalls are...