ZyXEL Communications Prestige 1600 - Manual (Page 91)

Prestige 1600 Universal Access Concentrator
Filter Configuration 10-9
Packet
into IP Filter
Matched
Matched
Yes
Action Matched
Action Not Matched
More?
No
Filter Active?
Check
IP Protocol
Drop
Drop Packet Accept Packet
Drop Forward Check Next Rule
Check Next Rule
Check Next Rule
Forward
Not Matched
Yes
No
Check Src
IP Addr
Apply SrcAddrMask
to Src Addr
Matched
Check Dest
IP Addr
Apply DestAddrMask
to Dest Addr
Not Matched
Not Matched
Check Src &
Dest Port
Matched
Not Matched
Figure 10-7 Executing an IP Filter
10.5.2 Device Filter Rule
This section shows you how to configure a device filter rule. The purpose of device rules is to allow you to filter
non-IP/IPX packets. For IP and IPX, it is generally easier to use the protocol rules directly.
For Device 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, e.g.,
FFFFFFFF .
To configure a device rule, select Device Filter Rule in the Filter Type field and press [ENTER] to open Menu
21.1.1 - Device Filter Rule, as shown below.