ZyXEL Communications 802.11g ADSL 2+ 4-Port Security Gateway HW-D Series - Manual (Page 205)

P-662H/HW-D Series User’s Guide
Chapter 12 Anti-Virus Packet Scan 205
This is an Internet file transfer service that operates on the Internet and over TCP/IP
networks. A system running the FTP server accepts commands from a system running an
FTP client. The service allows users to send commands to the server for uploading and
downloading files.
Note: The anti-virus packet scan on the ZyXEL Device offers the first defense against
possible virus attacks on your network. It is not a replacement of the anti-virus
client software that you may install on network computers.
12.3.1 How the ZyXEL Device Virus Scan Works
The following describes the virus scanning process on the ZyXEL Device.
1 The ZyXEL Device first identifies the packet types (SMTP, POP3, HTTP and FTP
through standard ports only) from the network traffic.
2 If the packets are not session connection setup packets (such as SYN, ACK and FIN), the
ZyXEL Device records the sequence of the packets.
3 The scanning engine scans the content of the packet for virus.
4 If a virus pattern is matched, the ZyXEL Device “cleans” the virus by deleting the
infected packet and alerts the intended computer user(s).
Note: Since the ZyXEL Device “destroys” a file by deleting the infected portion of the
file content, you cannot open the file.
12.3.2 Limitations of the ZyXEL Device Packet Scan
The ZyXEL Device does not scan the following types of file for virus:
• Compressed or zipped files
• Simultaneous file downloads (for example, when you use the FlashGet download
program).
• When a virus is detected, an alert message is displayed in Miscrosoft Windows-based
operation systems only.
1
12.4 Anti-Virus Packet Scan Configuration
Note: Before you can use the anti-virus packet scan on the ZyXEL Device, you must
register for the anti-virus service in the Registration and Virus Information
Update screen (see the
Section 12.5 on page 207 section for more
information).
1. For Windows 98/Me, refer to the antivirus supplement for requirements.