Firewalls

3

1

Firewalls: What Are They?

1.1 Chapter objectives

■ Showing the components of a firewall

■ Showing what firewalls can and cannot do

■ Comparing firewall types

■ Using application proxies

■ Showing the four-way security model

Today, when an organization connects its private network to the

Internet, security has to be a primary concern. In the past, before the

widespread interest in the Internet, most network administrators were

concerned about attacks on their networks from within, perhaps from

disgruntled workers. But for most organizations now connecting to

the Internet and big business and big money moving toward elec-

tronic commerce at warp speed, the ...