ZyXEL Communications P-660HN-F1, User Manual

Page: 186 / 366

Chapter 13 Firewall
ADSL Series User’s Guide
186
It is designed to protect against Denial of Service (DoS) 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/WLAN 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.
The LAN (Local Area Network) port attaches to a network of computers, which needs security from
the outside world. These computers will have access to Internet services such as e-mail, FTP and
the World Wide Web. However, "inbound access" is not allowed (by default) unless the remote host
is authorized to use a specific service.
ICMP
Internet Control Message Protocol (ICMP) is a message control and error-reporting protocol
between a host server and a gateway to the Internet. ICMP uses Internet Protocol (IP) datagrams,
but the messages are processed by the TCP/IP software and directly apparent to the application
user.
Finding Out More
See Section 13.4 on page 188 for advanced technical information on firewall.
13.2 The General Screen
Use this screen to enable or disable the ZyXEL Device’s firewall. Click Security > Firewall to open
the General screen.
Figure 92
Security > Firewall > General
The following table describes the labels in this screen.
Table 53
Security > Firewall > General
LABEL DESCRIPTION
Firewall Select Enable to activate the firewall. The ZyXEL Device performs access control and
protects against Denial of Service (DoS) attacks when the firewall is activated.
Apply Click Apply to save your changes.
Cancel Click Cancel to restore your previously saved settings.