TMS zl Management and Configuration Guide ST.1.1.100226

4-8
Firewall
General Firewall Concepts
ALGs are covered in more detail in “Application-Level Gateways (ALGs)” on
page 4-87 and “Enable and Disable ALGs” on page 4-96.
The TMS zl Module includes ALGs for several specific applications. In keeping
with best security practices, however, only one ALG—the FTP ALG—is
enabled by default. You must explicitly enable any other ALGs that your
organization might need.
Packet Flow
The core component of the TMS zl Module is the firewall, which controls the
packet flow through the other components of the TMS zl Module. The example
below show a simplified packet flow when all of the features are in use. More
detailed packet-flow diagrams are in the help files on the module.
Figure 4-1. Simplified Packet Flow through the TMS zl Module in Routing Mode