Implementing Cisco Networking Solutions

Application inspection

There are some protocols that embed IP addressing information within the payload. For example, voice packets where voice control packets connect to the central server with a phone number and the called number's IP address is returned by the call control server. This communication happens in the payload. The client now starts to send packets to the new IP address. If the packets are going through the firewall, the firewall should be aware that a new IP stream would flow between the IP addresses of the calling phone and the called phone. This requires the firewall to look deep into the application payloads to analyze this information. ASA firewalls support application inspection for a variety of protocols such as HTTP, ...