ZyXEL p-334 Manual Do Utilizador
Prestige 334 User’s Guide
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Chapter 27 Filter Configuration
Figure 139 Executing an IP Filter
27.2.3 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 Prestige 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 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 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.
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 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.
To configure a generic rule, select Generic Filter Rule in the Filter Type field in menu
21.1.4.1 and press [ENTER] to open Generic Filter Rule, as shown below.
21.1.4.1 and press [ENTER] to open Generic Filter Rule, as shown below.