Chapter 21 Security Policy; Overview - ZyXEL Communications ZyWALL 110 User Manual

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Security Policy

21.1 Overview

A security policy is a template of security settings that can be applied to specific traffic at specific
times. The policy can be applied:
• to a specific direction of travel of packets (from / to)
• to a specific source and destination address objects
• to a specific type of traffic (services)
• to a specific user or group of users
• at a specific schedule
The policy can be configured:
• to allow or deny traffic that matches the criteria above
• send a log or alert for traffic that matches the criteria above
• to apply the actions configured in the UTM profiles (application patrol, content filter, IDP, anti-
virus, anti-spam) to traffic that matches the criteria above
Note: Security policies can be applied to both IPv4 and IPv6 traffic.
The security policies can also limit the number of user sessions.
The following example shows the ZyWALL/USG's default security policies behavior for a specific
direction of travel of packets. WAN to LAN traffic and how stateful inspection works. A LAN user can
initiate a Telnet session from within the LAN zone and the ZyWALL/USG allows the response.
However, the ZyWALL/USG blocks incoming Telnet traffic initiated from the WAN zone and destined
for the LAN zone.
Figure 242 Default Directional Security Policy Example
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