ZyXEL Communications 2602HWL-DXA Manual Do Utilizador

Página de 218
 
 
Prestige 2602HWL-DxA Support Notes 
 
 
 
All contents copyright (c) 2005 ZyXEL Communications Corporation.   
171
 
How can I protect against IP spoofing attacks?    
The Prestige's firewall will automatically detect the IP spoofing and drop it if the firewall is turned on. If the 
firewall is not turned on we can configure a filter set to block the IP spoofing attacks. The basic scheme is as 
follows:   
For the input data filter:   
• 
Deny packets from the outside that claim to be from the inside   
• 
Allow everything that is not spoofing us   
Filter rule setup:   
• 
Filter type =TCP/IP Filter Rule   
• 
Active =Yes   
• 
Source IP Addr =a.b.c.d   
• 
Source IP Mask =w.x.y.z   
• 
Action Matched =Drop   
• 
Action Not Matched =Forward   
Where a.b.c.d is an IP address on your local network and w.x.y.z is your netmask:   
For the output data filters:   
• 
Deny bounceback packet   
• 
Allow packets that originate from us   
Filter rule setup:   
• 
Filter Type =TCP/IP Filter Rule