ZyXEL g-2000 plusv2 Guia Do Utilizador
ZyXEL G-2000 Plus v2 User’s Guide
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Chapter 28 Filter Configuration
Figure 164 Executing an IP Filter
28.2.3 Configuring a 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 ZyXEL device treats a packet as a byte stream as opposed to an IP or
IPX packet. You specify the portion of the packet to check with the Offset (from 0) and the
Length fields, both in bytes. The ZyXEL device 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 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.
IPX packet. You specify the portion of the packet to check with the Offset (from 0) and the
Length fields, both in bytes. The ZyXEL device 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 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.