ZyXEL Communications 1000 Benutzerhandbuch
Chapter 33 Anti-Virus
ZyWALL USG 1000 User’s Guide
549
2
If the packets are not session connection setup packets (such as SYN, ACK and
FIN), the ZyWALL records the sequence of the packets.
FIN), the ZyWALL records the sequence of the packets.
3
The scanning engine checks the contents of the packets for virus.
4
If a virus pattern is matched, the ZyWALL removes the infected portion of the file
along with the rest of the file. The un-infected portion of the file before a virus
pattern was matched still goes through.
along with the rest of the file. The un-infected portion of the file before a virus
pattern was matched still goes through.
5
If the send alert message function is enabled, the ZyWALL sends an alert to the
file’s intended destination computer(s).
file’s intended destination computer(s).
Note: Since the ZyWALL erases the infected portion of the file before sending it, you
may not be able to open the file.
Notes About the ZyWALL Anti-Virus
The following lists important notes about the anti-virus scanner:
1
The ZyWALL anti-virus scanner can detect polymorphic viruses.
2
When a virus is detected, an alert message is displayed in Microsoft Windows
computers. Refer to
computers. Refer to
if your Windows computer does not
display the alert messages.
3
Changes to the ZyWALL’s anti-virus settings affect new sessions (not the sessions
that already existed before you applied the changed settings).
that already existed before you applied the changed settings).
4
The ZyWALL does not scan the following file/traffic types:
• Simultaneous downloads of a file using multiple connections. For example,
when you use FlashGet to download sections of a file simultaneously.
• Encrypted traffic. This could be password-protected files or VPN traffic where
the ZyWALL is not the endpoint (pass-through VPN traffic).
• Traffic through custom (non-standard) ports. The only exception is FTP traffic.
The ZyWALL scans whatever port number is specified for FTP in the ALG
screen.
• ZIP file(s) within a ZIP file.
Finding Out More
• See
for related information on these screens.
• See
for anti-virus background information.