ZyXEL Communications Prestige 661H Series, User Manual

Page: 338 / 547

Prestige 661H/HW Series User’s Guide
Chapter 33 Filter Configuration 338
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.
To configure a generic rule select an empty filter set in menu 21, for example 5. Select
Generic Filter Rule in the Filter Type field and press [ENTER] to open Menu 21.1.5.1 –
Generic Filter Rule , as shown in the following figure.
Figure 209 Menu 21.1.5.1 Generic Filter Rule
The next table describes the fields in the Generic Filter Rule menu.
Menu 21.1.5.1 - Generic Filter Rule
Filter #: 5,1
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:
Table 116 Menu 21.1.5.1 Generic Filter Rule
FIELD DESCRIPTION
Filter # This is the filter set, filter rule coordinates, for instance, 2, 3 refers to the second filter
set and the third rule of that set.
Filter Type Press [SPACE BAR] and then [ENTER] to select a type of rule. Parameters displayed
below each type will be different. Choices are Generic Filter Rule or TCP/IP Filter
Rule .
Active Select Yes to turn on or No to turn off the filter rule.
Offset Type the starting byte of the data portion in the packet that you want to compare. The
range for this field is from 0 to 255.
Length Type the byte count of the data portion in the packet that you want to compare. The
range for this field is 0 to 8.
Mask Type the mask (in Hexadecimal) to apply to the data portion before comparison.
Value Type the value (in Hexadecimal) to compare with the data portion.
More If Yes , a matching packet is passed to the next filter rule before an action is taken or
else the packet is disposed of according to the action fields.
If
More is Yes , then Action Matched and Action Not Matched will be N/A .