ZyXEL Communications 314 PLUS 7.1.1 The Filter Structure of the Prestige, Figure 7-1Outgoing Packet Filtering Process

Prestige 314 PLUS Broadband Sharing Gateway with 4-Port Switch

Call Filtering

No

Built-in

No

User-defined

No

Active Data

match

Outgoing

Data

match

default

Call Filters

match

Initiate call

Packet

Call Filters

(if applicable)

if line not up

Send packet

and reset

Match

Match

Match

Idle Timer

Drop

Drop packet

Drop packet

packet

if line not up

if line not up

Or

Or

Send packet

Send packet

but do not reset

but do not reset

Idle Timer

Idle Timer

Figure 7-1 Outgoing Packet Filtering Process

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

7.1.1 The Filter Structure of the Prestige

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.

Three sets of factory default filter rules have been configured in menu 21 to prevent NetBIOS traffic from triggering calls and to prevent incoming telnetting and FTP connections from the WAN side. A summary of their filter rules is shown in the figures that follow.

The following diagram illustrates the logic flow when executing a filter rule.

7-2 Filter Configuration