Prestige 324 User’s Guide
23-16
Filter Configuration
Generic and TCP/IP filter rules are discussed in more detail in the next section. When NAT (Network
Address Translation) 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 and port number before NAT for outgoing
packets and after NAT 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 port or any other hardware port. The
following diagram illustrates this.
Figure 23-12 Protocol and Device Filter Sets
23.5 Firewall Versus Filters
Firewall configuration is discussed in the
firewall
chapters
of this manual. Further comparisons are also made
between filtering, NAT and the firewall.
23.6 Applying a Filter
This section shows you where to apply the filter(s) after you design it (them). The Prestige already has filters
to prevent NetBIOS traffic from triggering calls, and block incoming telnet, FTP and HTTP connections.
Summary of Contents for P-324
Page 1: ...Prestige 324 Intelligent Broadband Sharing Gateway User s Guide Version V3 61 JF 0 April 2004 ...
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Page 87: ...Prestige 324 User s Guide WAN Screens 6 17 Figure 6 10 Dial Backup Setup ...
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Page 310: ...IX Part IX Appendices and Index This section provides some Appendices and an Index ...
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