ZyXEL Communications Prestige 642R Series - Manual (Page 98)

Prestige 642R Series ADSL Router
8-2 Filter Configuration
8.1.1 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. 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: