HP TMS zl Module Security Administrator's Guide

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Managing TMS zl Firewalls
Viewing Firewall Configurations
Viewing Port Triggers
Some applications dynamically negotiate ports other than well-known ports
for data transfer, such as FTP and HTTP. The firewall in the TMS zl Module
can handle these dynamic connections through user-configured port triggers.
The intelligence to handle these dynamic connections is sometimes called an
application-level gateway (ALG). However, ALG’s can be more complex than
a simple Port Trigger.
A port trigger policy is activated or “triggered” when the initial connection is
formed. The connection through the dynamically connected port can be in the
same direction or in the opposite direction of the initial connection.
Selecting the TMS zl node or a specific TMS zl module and clicking the Port
Triggers subtab displays another level of subtabs. Selecting the Port Triggers
subtab displays a subtab for each type of TMS zl Port Trigger policy:
Port Trigger Policies
The Policies subtab on the Firewall > Port Triggers subtab for the TMS zl node
or a specific TMS zl module displays the following information for all Port
Trigger policies configured on the selected TMS zl device(s):