Default Firewall; Three-Legged Firewall - Nortel Secure 4134 Configuration

24 Firewall and NAT Fundamentals
Default firewall
The following figure shows the default firewall configuration: a corp trusted
zone with all outbound connections allowed and an internet untrusted zone
with all incoming connections blocked. In addition, all ALGs are enabled.
Figure 1
Default firewall
Three-legged firewall
A typical three-legged firewall configuration consists of the following three
virtual firewalls:
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•
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In this configuration, untrusted SSH and IKE connections to the router
itself are allowed. Trusted and untrusted HTTP connections to a DMZ web
server are allowed. And the default, corp trusted zone with all outbound
connections are allowed.
Copyright © 2007, Nortel Networks
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Corp – An organization's private trusted network
Dmz – An organization hosting its web/ ftp/ mail server to public
Internet – The public untrusted network
Nortel Secure Router 4134
Security — Configuration and Management
NN47263-600 01.02 Standard
10.0 3 August 2007