CTC Union SHDTU03-ET10R, Руководство пользователя

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Chapter 3. Set-Up
3-16
NAT/DMZ
NAT (Network Address Translation) is the translation of an Internet
Protocol address (IP address) used within one network to a different IP
address known within another network. One network is designated as
the inside network (private) and the other as the outside network
(public). Typically, a company maps its local inside network addresses
to one or more global outside IP addresses and reverses the global IP
addresses of incoming packets back into local IP addresses. This
ensures security since each outgoing or incoming request must go
through a translation process, that also offers the opportunity to qualify
or authenticate the request or match it to a previous request. NAT also
conserves on the number of global IP addresses that a company needs
and allows the company to use a single IP address for its communication in the Internet world.
DMZ (demilitarized zone) is a computer host or small network inserted as a “neutral zone” between
a company's private network and the outside public network. It prevents outside users from getting
direct access to a server that has company private data.
In a typical DMZ configuration for an enterprise, a separate computer or host receives requests
from users within the private network to access via Web sites or other companies accessible on
the public network. The DMZ host then initiates sessions for these requests to the public network.
However, the DMZ host is not able to initiate a session back into the private network. It can only
forward packets that have already been requested.
Users of the public network outside the
company can access only the DMZ host.
The DMZ may typically also have the
company’s Web pages so these could
serve the outside world. However, the
DMZ provides access to no other
company data. In the event that an
outside user penetrated the DMZ host’s
security, the Web pages might be
corrupted, but no other company
information would be exposed.
Press NAT/DMZ to setup the parameters.