PROLiNK Hurricane 9200/S, Руководство пользователя

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Chapter 14 . Configuring Filters and Blocking Protocols
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The IP Filter Configuration page enables you to configure the
following global IP filter settings.
Security Level: This setting determines which IP filter rules
take effect, based on the security level specified in each
rule. For example, when High is selected, only those rules
that are assigned a security value of High will be in effect.
The same is true for the Medium and Low settings. When
None is selected, IP filtering is disabled.
Private/Public/DMZ Default Action: This setting specifies
a default action to be taken (Accept or Deny) on private,
public, or DMZ-type device interfaces when they receive
packets that do not match any of the filtering rules. You can
specify a different default action for each interface type.
(You specify an interface's type when you create the
interface; see the PPP configuration page, for example.)
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A public interface typically connects to the Internet.
PPP, EoA, and IPoA interfaces are typically public.
Packets received on a public interface are subject to
the most restrictive set of firewall protections defined in
the software. Typically, the global setting for public
interfaces is Deny, so that all accesses to your LAN
initiated from external computers are denied (discarded
at the public interface), except for those allowed by a
specific IP filter rule.
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A private interface connects to your LAN, such as the
Ethernet interface. Packets received on a private
interface are subject to a less restrictive set of
protections, because they originate within the network.
Typically, the global setting for private interfaces is
Accept, so that LAN computers have access to the
ADSL/Ethernet routers' Internet connection.
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The term DMZ (de-militarized zone), in Internet
networking terms, refers to computers that are
available for both public and in-network accesses
(such as a company's public Web server). Packets
received on a DMZ interface — whether from a LAN or
external source—are subject to a set of protections that
is in between public and private interfaces in terms of
restrictiveness. The global setting for DMZ-type
interfaces may be set to Deny so that all attempts to
access these servers are denied by default; the
administrator may then configure IP filter rules to allow
accesses of certain types.