ZyXEL Communications IDP 10 Manual Do Utilizador

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IDP Support Notes 
 
 
  35
 
If the IDP is placed on the entry point of a Wireless LAN network, we recommend 
you to apply policy check on the WAN interface, due to the lack of security protection 
of Wireless LAN. 
 
 
In User-defined policy, what’s the meaning of Matching Offset, 
Matching Depth?   
 
Matching Offset defines the payload start point. If Protocol type is IP, then the 
matching starting point is at the end of the layer-3 header; otherwise, it would start 
matching from the end of the layer-4 header.   
Matching Depth is the length of the payload to search for a match. 
The Offset and Depth apply to all strings.   
 
How does IDP check multiple contents? 
 
For multiple contents, the order in which they’re found doesn’t matter (that is string 3 
could be found before string 1 as long as it’s within the depth defined) and string 
overlaps are also allowed. The multiple contents should be all found in one packet for 
a match. 
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