ZyXEL Communications LTE5121, User Manual

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Chapter 12 Firewall
LTE-5121 User’s Guide
126
12.1.2 What You Need to Know
Firewall
The LTE Device’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 designed to protect against Denial of Service (DoS) attacks when activated. The LTE Device's
purpose is to allow a private Local Area Network (LAN) to be securely connected to the Internet.
The LTE 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 LTE 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.
The LTE Device has one LTE WAN interface and four Ethernet LAN ports, which separate the
network into two areas. The WAN (Wide Area Network) connects 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.
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 12.6 on page 132 for advanced technical information on firewall.
12.2 The General Screen
Use this screen to enable or disable the LTE Device’s firewall and set the security level. Click
Security > Firewall to open the General screen.