P-2302R-P1 Series User’s Guide
Chapter 13 Firewall
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C
H A P T E R
13
Firewall
Use these screens to enable, configure and disable the firewall that protects your ZyXEL
Device and your LAN from unwanted or malicious traffic.
13.1 Firewall Overview
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. 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.
13.1.1 Stateful Inspection Firewall.
Stateful inspection firewalls restrict access by screening data packets against defined access
rules. They make access control decisions based on IP address and protocol. They also
"inspect" the session data to assure the integrity of the connection and to adapt to dynamic
protocols. These firewalls generally provide the best speed and transparency; however, they
may lack the granular application level access control or caching that some proxies support.
Firewalls, of one type or another, have become an integral part of standard security solutions
for enterprises.
13.1.2 About the ZyXEL Device Firewall
The ZyXEL Device firewall is a stateful inspection firewall and is designed to protect against
Denial of Service attacks when activated. The ZyXEL Device's purpose is to allow a private
Local Area Network (LAN) to be securely connected to the Internet. The ZyXEL Device can
be used to prevent theft, destruction and modification of data, as well as log events, which may
be important to the security of your network.
The ZyXEL Device is installed between the LAN and a broadband modem connecting to the
Internet. This allows it to act as a secure gateway for all data passing between the Internet and
the LAN.
Summary of Contents for P-2302R-P1 Series
Page 1: ...P 2302R P1 Series VoIP ATA Station Gateway User s Guide Version 3 60 Edition 1 5 2006...
Page 2: ......
Page 5: ...P 2302R P1 Series User s Guide Certifications 5...
Page 10: ...P 2302R P1 Series User s Guide 10 Customer Support...
Page 38: ...P 2302R P1 Series User s Guide 38 Chapter 1 Introducing the ZyXEL Device...
Page 46: ...P 2302R P1 Series User s Guide 46 Chapter 2 Introducing the Web Configurator...
Page 106: ...P 2302R P1 Series User s Guide 106 Chapter 7 LAN...
Page 125: ...P 2302R P1 Series User s Guide Chapter 9 SIP 125 Figure 60 VoIP SIP SIP Settings Advanced...
Page 130: ...P 2302R P1 Series User s Guide 130 Chapter 9 SIP...
Page 140: ...P 2302R P1 Series User s Guide 140 Chapter 10 Phone...
Page 146: ...P 2302R P1 Series User s Guide 146 Chapter 11 Phone Book...
Page 160: ...P 2302R P1 Series User s Guide 160 Chapter 14 Content Filter...
Page 174: ...P 2302R P1 Series User s Guide 174 Chapter 15 Bandwidth MGMT...
Page 184: ...P 2302R P1 Series User s Guide 184 Chapter 17 Static Route...
Page 208: ...P 2302R P1 Series User s Guide 208 Chapter 19 System...
Page 224: ...P 2302R P1 Series User s Guide 224 Chapter 20 Logs...
Page 234: ...P 2302R P1 Series User s Guide 234 Appendix A Product Specifications...
Page 256: ...P 2302R P1 Series User s Guide 256 Appendix C IP Subnetting...
Page 258: ...P 2302R P1 Series User s Guide 258 Appendix D SIP Passthrough...
Page 288: ...P 2302R P1 Series User s Guide 288 Appendix G Services...
