Prestige 1600 Universal Access Concentrator

Packet

into IP Filter

Filter Active?

Yes

Apply SrcAddrMask

to Src Addr

Check Src

IP Addr

Matched

Apply DestAddrMask

to Dest Addr

Check Dest

IP Addr

Matched

Check

IP Protocol

Matched

Check Src &

Dest Port

Matched

More?

No

Action Matched

No

Not Matched

Not Matched

Not Matched

Not Matched

Yes

Action Not Matched

Check Next Rule

Check Next Rule

 

Drop

Forward

DropForward

Drop Packet

Check Next Rule

Accept Packet

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.

Filter Configuration

10-9