ZyXEL P-660HW-D1 Guia Do Utilizador
Prestige 660H/HW Series User’s Guide
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Chapter 31 Filter Configuration
Figure 185 Executing an IP Filter
31.4.2 Generic Filter Rule
This section shows you how to configure a generic filter rule. The purpose of generic rules is
to allow you to filter non-IP packets. For IP, it is generally easier to use the IP rules directly.
to allow you to filter non-IP packets. For IP, it is generally easier to use the IP rules directly.
For generic rules, the Prestige treats a packet as a byte stream as opposed to an IP packet. You
specify the portion of the packet to check with the Offset (from 0) and the Length fields, both
in bytes. The Prestige applies the Mask (bit-wise ANDing) to the data portion before
comparing the result against the Value to determine a match. The Mask and Value fields are
specified in hexadecimal numbers. Note that it takes two hexadecimal digits to represent a
byte, so if the length is 4, the value in either field will take 8 digits, for example, FFFFFFFF.
specify the portion of the packet to check with the Offset (from 0) and the Length fields, both
in bytes. The Prestige applies the Mask (bit-wise ANDing) to the data portion before
comparing the result against the Value to determine a match. The Mask and Value fields are
specified in hexadecimal numbers. Note that it takes two hexadecimal digits to represent a
byte, so if the length is 4, the value in either field will take 8 digits, for example, FFFFFFFF.