ZyXEL Communications Prestige 641, Руководство пользователя, Страница: 82 / 117

Prestige 641 ADSL Internet Access Router
8-4
Filter Configuration
Table 8-2 Abbreviations Used If Filter Type Is IP
Abbreviation Description
Pr Protocol
SA Source Address
SP Source Port number
DA Destination Address
DP Destination Port number
l
If the filter type is GEN (generic), the following abbreviations listed in the following table will be
used.
Table 8-3 Abbreviations Used If Filter Type Is GEN
Abbreviation Description
Off Offset
Len Length
Refer to the next section for information on configuring the filter rules.
8.3 Configuring a Filter Rule
To configure a filter rule, enter its number in Menu 21.1 - Filter Rules Summary and press Enter to open
Menu 21.1.1 for the rule.
There are three types of filter rules: TCP/IP, IPX and Generic. Depending on the type of rule, the
parameters below the type will be different. Use the space bar to select the type of rule that you wish to
create in the Filter Type field and press Enter to open the respective menu.
To speed up filtering, all rules in a filter set must be of the same class, i.e., protocol filters or generic filters.
The class of a filter set is determined by the first rule that you create. When applying the filter sets to a
port, separate menu fields are provided for protocol and device filter sets. If you include a protocol filter set
in a device filters field or vice versa, the Prestige will warn you and will not allow you to save.
8.4 Filter Types and SUA
There are two types of filter rules, Device Filter (Generic) rules and Protocol Filter (TCP/IP and IPX)
rules. Device Filter rules act on the raw data from/to LAN and WAN. Protocol Filter rules act on the IP
and IPX packets. Generic and TCP/IP filter rules are discussed in more detail in the next section. When
NAT/SUA (Network Address Translation/Single User Account) is enabled, the inside IP address and port
number are replaced on a connection-by-connection basis, which makes it impossible to know the exact
address and port on the wire. Therefore, the Prestige applies the protocol filters to the “native” IP address