CTC Union SHDTU03b, User Manual

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8.6 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 the inside network and the
other is the outside. Typically, a company maps its local inside network
addresses to one or more global outside IP addresses and reverse the global IP
addresses of incoming packets back into local IP addresses. This ensure
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 lets the company to use a single IP
address of its communication in the Internet world.
DMZ (demilitarized zone) is a computer host or small network inserted as a
“neutral zone” between a company 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.
If you want to enable the NAT/DMZ
functions, click Enable. Enable the DMZ
host Function is used the IP address
assigned to the WAN for enabling DMZ
function for the virtual IP address.
Multi-DMZ: Some users who have two or
more global IP addresses assigned by ISP
can be used the multi DMZ. The table is for
the mapping of global IP address and virtual
IP address.