Firewalls - Watchguard Firebox X15 User Manual

Introduction to Network Security

Firewalls

A firewall divides your internal network from the Internet to
decrease risk from an external attack. We refer to the computers and
networks on the Internet as the external network. The computers on
the internal side of the firewall are protected. We refer to these as
trusted computers. The figure below shows how a firewall divides
the trusted computers from the Internet.
Firewalls use access policies to identify different types of informa-
tion. They can also control which services or ports the protected
computers can use on the Internet (outbound access). Many fire-
walls have sample security policies and users can select the policy
that is best for them. With others—such as the Firebox® X Edge—the
user can customize these policies.
8 WatchGuard Firebox X Edge