ZyXEL Communications Generic Filter Rule, ExpWave 240B Secure Outdoor Ethernet Radio Link

ExpWave 240B Secure Outdoor Ethernet Radio Link

Figure 9-5 Executing an IP Filter

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 ExpWave 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 ExpWave 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 in the Menu 21.1.1 and press Enter to open Generic Filter Rule, as shown below.

Menu 21.1.1 - Generic Filter Rule

Filter #: 4,1

Filter Type= Generic Filter Rule

Active= No
Offset= 0
Length= 0
Mask= N/A
Value= N/A	Log= None
More= No

Action Matched= Check Next Rule

Action Not Matched= Check Next Rule

Press ENTER to Confirm or ESC to Cancel:

Press Space Bar to Toggle.

Figure 9-6 Menu 21.4.1 - Generic Filter Rule

The following table describes the fields in the Generic Filter Rule Menu.

Table 9-5 Generic Filter Rule Menu Fields

Field		Description	Option
Filter #		This is the filter set, filter rule co-ordinates, i.e., 2,3 refers to the second filter
		set and the third rule of that set.
Filter Type		Use the space bar to toggle between both types of rules. Parameters	Generic Filter
		displayed below each type will be different.	Rule/ TCP/IP
			Filter Rule
Active		Select Yes to turn on the filter rule.	Yes/No
Offset	Enter the starting byte of the data portion in the packet that you wish to		Default = 0
		compare. The range for this field is from 0 to 255.
Length		Enter the byte count of the data portion in the packet that you wish to	Default = 0
		compare. The range for this field is 0 to 8.
Mask	Enter the mask (in Hexadecimal) to apply to the data portion before
		comparison.
Value		Enter 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	Yes / N/A
		taken; 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.
Log		Select the logging option from the following:
		None – No packets will be logged.	None
		Action Matched - Only packets that match the rule parameters will be
			Action
		logged.
			Matched
		Action Not Matched - Only packets that do not match the rule parameters

9-6 Filter Setup