Cisco 7609-S Configuration Guide - Page 111

Chapter 5 Configuring the Firewall Mode Routed Mode Overview The following steps describe how data moves through the FWSM (see Figure 5-3): 1. A user on the inside network requests a web page from the DMZ web server using the destination address of 10.1.1.3. 2. The FWSM receives the packet and because it is a new session, the FWSM verifies that the packet is allowed according to the terms of the security policy (access lists, filters, AAA). For multiple context mode, the FWSM first classifies the packet according to either a unique interface or a unique destination address associated with a context; the destination address is associated by matching an address translation in a context. In this case, the interface is unique; the web server IP address does not have a current address translation. 3. The FWSM then records that a session is established and forwards the packet out of the DMZ interface. 4. When the DMZ web server responds to the request, the packet goes through the fast path, which lets the packet bypass the many lookups associated with a new connection. 5. The FWSM forwards the packet to the inside user. An Outside User Attempts to Access an Inside Host Figure 5-4 shows an outside user attempting to access the inside network. Figure 5-4 Outside to Inside www.example.com Outside 10.1.2.1 209.165.201.2 FWSM 10.1.1.1 Inside DMZ User 10.1.2.27 92891 OL-20748-01 Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM 5-5