ZyXEL Communications 480 - Manual (Page 103)

Prestige 480 ISDN Router
Filter Configuration 7-9
Once you have completed filling in Menu 21.1.1 - TCP/IP Filter Rule, press [Enter] at the message [Press
Enter to Confirm] to save your configuration, or press [Esc] to cancel. This data will now be displayed on
Menu 21.1 - Filter Rules Summary.
7.3.3 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 7-7 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: