ZyXEL Communications P-334W User Manual

Prestige 334W User’s Guide 

30-2  

 

Filter Configuration 

For incoming packets, your Prestige applies data filters only. Packets are processed depending upon whether 
a match is found. The following sections describe how to configure filter sets. 

A filter set consists of one or more filter rules. Usually, you would group related rules, e.g., all the rules for 
NetBIOS, into a single set and give it a descriptive name. The Prestige allows you to configure up to twelve 
filter sets with six rules in each set, for a total of 72 filter rules in the system. You cannot mix device filter 
rules and protocol filter rules within the same set. You can apply up to four filter sets to a particular port to 
block multiple types of packets. With each filter set having up to six rules, you can have a maximum of 24 
rules active for a single port. 

Sets of factory default filter rules have been configured in menu 21 to prevent NetBIOS traffic from 
triggering calls and to prevent incoming telnet sessions. A summary of their filter rules is shown in the 
figures that follow. 

The following figure illustrates the logic flow when executing a filter rule. See also Figure 30-7 for the logic 
flow when executing an IP filter. 

Data 

Filtering

 

Outgoing

Packet

Drop

packet

Built-in
default

Call Filters

User-defined

Call Filters

(if applicable)

Initiate call

if line not up

Active Data

Send packet

and reset

Idle Timer

Or

Or

Drop packet
if line not up

Drop packet
if line not up

Send packet

but do not reset

Idle Timer

Send packet

but do not reset

Idle Timer

Match

Match

Match

No

match

No

match

No

match

Call Filtering