ZyXEL Communications ARMOR G1, User Manual

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Chapter 12 Security
NBG6818 User’s Guide
124
About the NBG6818 Firewall
The NBG6818’s firewall feature physically separates the LAN and the WAN and acts as a secure
gateway for all data passing between the networks.
It is a stateful inspection firewall and is designed to protect against Denial of Service attacks when
activated (click
the IPv4 Firewall or IPv6 Firewall tab under Security and then click the Enable Firewall
check box). The NBG6818's purpose is to allow a private Local Area Network (LAN) to be securely
connected to the Internet. The NBG6818 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 NBG6818 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.
The NBG6818 has one Ethernet WAN port and four Ethernet LAN ports, which are used to physically
separate the network into two areas.The WAN (Wide Area Network) port attaches to the broadband
(cable or DSL) modem to the Internet.
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.
Guidelines For Enhancing Security With Your Firewall
1
Change the default password via Web Configurator.
2
Think about access control before you connect to the network in any way, including attaching a
modem to the port.
3
Limit who can access your router.
4
Don't enable any local service (such as NTP) that you don't use. Any enabled service could present a
potential security risk. A determined hacker might be able to find creative ways to misuse the enabled
services to access the firewall or the network.
5
For local services that are enabled, protect against misuse. Protect by configuring the services to
communicate only with specific peers, and protect by configuring rules to block packets for the services
at specific interfaces.
6
Protect against IP spoofing by making sure the firewall is active.
7
Keep the firewall in a secured (locked) room.
12.2 IPv4 Firewall Screen
Use this screen to enable or disable the NBG6818’s IPv4 firewall. Click Settings > Firewall > IPv4 Firewall to
show the following screen.