ZyXEL Communications ZyWALL 1000 User Manual

ZyWALL USG 1000 User’s Guide

This chapter describes how to use application patrol for the ZyWALL. It provides an overview 
first and then introduces the screens. See 

 for related information on 

these screens.

Application patrol provides a convenient way to manage the use of various applications on the 
network. It manages general protocols (for example, http and ftp) and instant messenger (IM), 
peer-to-peer (P2P), Voice over IP (VoIP), and streaming (RSTP) applications. You can even 
control the use of a particular application’s individual features (like text messaging, voice, 
video conferencing, and file transfers). Application patrol also has powerful bandwidth 
management including traffic prioritization to enhance the performance of delay-sensitive 
applications like voice and video.

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The ZyWALL checks firewall rules before it checks application patrol rules for 
traffic going through the ZyWALL.

If you want to use a service, make sure both the firewall and application patrol allow the 
service’s packets to go through the ZyWALL.
Application patrol examines every TCP and UDP connection passing through the ZyWALL 
and identifies what application is using the connection. Then, you can specify, by application, 
whether or not the ZyWALL continues to route the connection.

There are two ways the ZyWALL can identify the application. The first approach is called 
auto. In this approach, the ZyWALL looks at the IP payload (OSI level-7) and attempts to 
match it with known patterns for specific applications. Usually, this occurs at the beginning of 
a connection, when the payload is more consistent across connections, and the ZyWALL 
examines several packets to make sure the match is correct.