AMG1202-T10B/AMG1302-T10B
Support Notes
18
All contents copyright © 2013 ZyXEL Communications Corporation.
Firewall FAQ
General
1. What is a network firewall?
A firewall is a system or a 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. The firewall can be
thought of two mechanisms: One to block the traffic, and the other to permit
traffic.
2. What makes AMG1302-T10B /AMG1202-T10B secure?
The AMG1302-T10B/AMG1202-T10B is pre-configured to automatically detect
and thwart Denial of Service (DoS) attacks such as Ping of Death, SYN Flood,
LAND attack, IP Spoofing, etc. It also uses stateful packet inspection to
determine if an inbound connection is allowed through the firewall to the
private LAN. The AMG1302-T10B /AMG1202-T10B supports Network Address
Translation (NAT), which translates the private local addresses to one or
multiple public addresses. This adds a level of security since the clients on the
private LAN are invisible to the Internet.
3. What are the basic types of firewalls?
Conceptually, there are three types of firewalls:
1. Packet Filtering Firewall
2. Application-level Firewall
3. Stateful Inspection Firewall
Packet Filtering Firewalls generally make their decisions based on the header
information in individual packets. These headers information include the
source, destination addresses and ports of the packets.
Application-level Firewalls generally are hosts running proxy servers, which
permit no traffic directly between networks, and which perform logging and
auditing of traffic passing through them. A proxy server is an application
gateway or circuit-level gateway that runs on top of general operating system
such as UNIX or Windows NT. It hides valuable data by requiring users to
