Security - Ovislink OV804WV User Manual

Removing a DMZ host
Step 1 Clear the DMZ Host Address.
Step 2 Click Save/Apply to apply the settings.

4.4.4 Security

Security is an important function of DSL. It protects resources
of a private network from users from other networks, and
prevents unauthorized Internet users from accessing private
networks connected to the Internet. All messages entering or
leaving the intranet (that is, the local network to which you are
connected) must pass through the security checks, which
checks each message and blocks those that do not meet the
specific security criteria.
There are three basic types of security techniques:

IP packet filtering: the system checks each packet
entering or leaving the network and accepts or rejects it
based on user-defined rules. Packet filtering is fairly
effective and transparent to users, but is difficult to
configure.

Circuit-level gateway: this process applies security
mechanisms when a TCP or UDP connection is
established. Once the connection is successful, packets
can be flown between the hosts without further checking.

MAC frame filtering: the system checks each frame
entering or leaving the network from layer 2. It accepts
and rejects frames according to user-defined rules.
A security management program can be configured in either of
the following basic ways:

A default-deny policy

A default-allow policy
A default-deny approach to security is much more secure, but
due to the difficulty in configuring and managing a network in
that fashion, many networks use the default-allow approach
instead.
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