ZyXEL Communications Prestige 643, User Manual

Page: 114 / 191

Prestige 643 ADSL Router
8-20 Filter Configuration
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 and port number before NAT/SUA for outgoing packets and after NAT/SUA for
incoming packets. On the other hand, the generic, or device filters are applied to the raw packets that
appear on the wire. They are applied at the point when the Prestige is receiving and sending the packets; i.e.
the interface. The interface can be an Ethernet, or any other hardware port. The following diagram
illustrates this.
Figure 8-16 Protocol and Device Filter Sets
8.5 Applying a Filter and Factory Defaults
This section shows you where to apply the filter(s) after you design it (them). Sets of factory default filter
rules have been configured in Menu 21 (but have not been applied) to filter telnet, FTP, NetBIOS and
PPPoE traffic. The PPPoE filter filters out all packets
except PPPoE packets going out from the Prestige to
the ISP or remote node.
Table 8-8 Input, Output and Call Filter Sets
FILTER SETS DESCRIPTION
Input Filter Sets: Apply filters for traffic coming into the Prestige. You may apply filter
rules for protocol or device filters. See the next section for
information on types of filters.
Output Filter
Sets: Apply filters for traffic going out of the Prestige. You may apply filter
rules for protocol or device filters. See earlier in this section for
information on types of filters.
Call Filter Sets: Apply filters to determine if a packet should be allowed to trigger a
call.