Firewalling with the ASA
The Adaptive Security Appliance (ASA) is Cisco’s firewall that was introduced in 2005 as the successor to the venerable PIX firewall. While it retains many components from the PIX, the ASA has evolved into a more Cisco IOS–like device, with some spillover from Cisco’s routing products. In recent years, the number of ASA features has increased exponentially. Understanding these features and how they are used is mandatory for any CCIE candidate.
Given the various options for deployment, the initial configuration of the ASA requires a bit of advanced planning. An ASA can be deployed in various forwarding modes with or without virtualization (contexts). Interfaces are given security values, ...