ZyXEL Communications 100 Series User Manual

 Chapter 28 Anti-Virus

ZyWALL USG 100/200 Series User’s Guide

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Since the ZyWALL erases the infected portion of the file before sending it, you 
may not be able to open the file.

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 

 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).

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. 

• See 

 for related information on these screens.

• See 

 for anti-virus background information.

• Before using anti-virus, see 

 for how to register for the anti-virus 

service. 

• You may need to customize the zones (in the Network > Zone) used for the anti-virus 

scanning direction.

Click Anti-X > Anti-Virus to display the configuration screen as shown next.