To protect their business assets, corporations usually deploy many of the following tools:
Firewalls to screen out unwanted traffic.
Web proxies to provide accessibility only to approved websites while preventing access to non-approved sites.
DMZs to provide secure ecommerce to the Internet at large while protecting the corporate network.
VPNs to provide secure remote access to corporate networks.
A typical deployment for a network is depicted in Figure 8-5. Note that two firewalls are used in this deployment in order to provide two levels of security, one for the DMZ systems behind the external firewall and even greater security for hosts behind the second firewall. The external firewall is not as ...