Chapter 5
Configuring the Firewall Mode
8.
An Outside User Visits a Web Server on the Inside Network
Figure 5-11
Figure 5-11
The following steps describe how data moves through the FWSM (see
1.
2.
3.
4.
Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM
OL-20748-01
The FWSM forwards the packet to the inside user.
shows an outside user accessing the inside web server.
Outside to Inside
Host
Internet
209.165.201.2
FWSM
209.165.201.1
209.165.200.230
Web Server
209.165.200.225
A user on the outside network requests a web page from the inside web server.
The FWSM receives the packet and adds the source MAC address to the MAC address table, if
required. Because it is a new session, it 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 a unique interface.
The FWSM records that a session is established.
If the destination MAC address is in its table, the FWSM forwards the packet out of the inside
interface. The destination MAC address is that of the downstream router, 209.186.201.1.
If the destination MAC address is not in the FWSM table, the FWSM attempts to discover the MAC
address by sending an ARP request and a ping. The first packet is dropped.
Management IP
209.165.201.6
Transparent Mode Overview
Figure
5-11):
5-15