ZyXEL Communications Prestige 480 - Manual (Page 154)

Prestige 480 Dual BRI ISDN Router
9-12 Filter Configuration
9.3.3 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.
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 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, e.g.,
FFFFFFFF .
To configure a generic rule, select Generic Filter Rule in the Filter Type field Menu 21.3.1 and press
[ENTER] to open Generic Filter Rule Menu, as shown below.
Figure 9-8 Menu 21.3.1 - Generic Filter Rule
The next table describes the fields in the Generic Filter Rule Menu.
Menu 21.3.1 - Generic Filter Rule
Filter #: 3,1
Filter Type= Generic Filter Rule
Active= No
Offset= 0
Length= 0
Mask= N/A
Value= N/A
More= No Log= None
Action Matched= Check Next Rule
Action Not Matched= Check Next Rule
Press ENTER to Confirm or ESC to Cancel: