ZyXEL Communications 802.11g ADSL 2+ 4-Port Security Gateway HW-D Series, User Manual

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P-662H/HW-D Series User’s Guide
204 Chapter 12 Anti-Virus Packet Scan
For maximum protection, you must keep the pattern file up-to-date.
12.2.1 Computer Virus Infection and Prevention
The follow describes a simplistic life cycle of a computer virus.
1 A computer gets a copy of a virus from an unknown source (such as the Internet, e-mail,
file sharing or any removable storage media). The virus is harmless until the execution of
an infected program.
2 The virus spreads to other files and programs on the computer.
3 The infected files are unintentionally sent to another computer thus starting the spread of
the virus.
4 Once the virus is spread through the network, the number of infected networked
computers can grow exponentially.
5 To prevent the spread of viruses, you need to install host-based anti-virus software on a
computer or buy an anti-virus system.
12.3 Introduction to the ZyXEL Device Anti-virus Packet Scan
The ZyXEL Device has an integrated signature-based anti-virus packet scan. Set up the
ZyXEL Device between your local network and the Internet. This way the ZyXEL Device can
scan incoming traffic to your local network from the Internet. Thus the ZyXEL Device helps
stop threats at the network edge before they reach the local host computers.
Figure 107 ZyXEL Device Anti-virus Application
Your ZyXEL Device is able to scan the following network traffic types for viruses:
• HTTP (Hyper Text Transfer Protocol)
This is the most common protocol used on the Internet. HTTP is the primary protocol
used for web sites and web browsers.
• Mail messages (SMPT, POP3)
• FTP (File Transfer Protocol)