ZyXEL Communications Corporation OX253P Manuale Utente
OX253P User’s Guide
119
C
H A P T E R
11
The Firewall Screens
11.1 Overview
Use the TOOLS > Firewall screens to manage OX253P’s firewall security
measures.
measures.
Originally, the term firewall referred to a construction technique designed to
prevent the spread of fire from one room to another. The networking term
"firewall" is a system or group of systems that enforces an access-control policy
between two networks. It may also be defined as a mechanism used to protect a
trusted network from an untrusted network. Of course, firewalls cannot solve
every security problem.
prevent the spread of fire from one room to another. The networking term
"firewall" is a system or group of systems that enforces an access-control policy
between two networks. It may also be defined as a mechanism used to protect a
trusted network from an untrusted network. Of course, firewalls cannot solve
every security problem.
A firewall is one of the mechanisms used to establish a network security perimeter
in support of a network security policy. It should never be the only mechanism or
method employed. For a firewall to guard effectively, you must design and deploy
it appropriately. This requires integrating the firewall into a broad information-
security policy. In addition, specific policies must be implemented within the
firewall itself.
in support of a network security policy. It should never be the only mechanism or
method employed. For a firewall to guard effectively, you must design and deploy
it appropriately. This requires integrating the firewall into a broad information-
security policy. In addition, specific policies must be implemented within the
firewall itself.
11.1.1 What You Can Do in This Chapter
• The Firewall Setting screen (
Section 11.2 on page 120
) lets you configure the
basic settings for your firewall.
• The Service Setting screen (
Section 11.3 on page 123
) lets you enable service
blocking, set up the date and time service blocking is effective, and to maintain
the list of services you want to block.
11.1.2 What You Need to Know
The following terms and concepts may help as you read through this chapter.
About the OX253P Firewall
The OX253P firewall is a stateful inspection firewall and is designed to protect
against Denial of Service attacks when activated. The OX253P's purpose is to
allow a private Local Area Network (LAN) to be securely connected to the Internet.
against Denial of Service attacks when activated. The OX253P's purpose is to
allow a private Local Area Network (LAN) to be securely connected to the Internet.