SMC Networks SMC7904WBRAS-N2 V2 - QUICK, Руководство пользователя

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C
HAPTER
8
| Services
NAT/NAPT Settings
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NAT/NAPT S
ETTINGS
Network Address Translation (NAT) is a standard method of mapping
multiple “internal” IP addresses to one “external” IP address on devices at
the edge of a network. For the router, the internal (local) IP addresses are
the IP addresses assigned to local PCs by the DHCP server, and the
external IP address is the IP address assigned to the specified WAN
interface.
The NAT function on the router enables the support of Virtual Servers, Port
Triggering, and other features.
Some applications, such as Internet gaming, videoconferencing, Internet
telephony and others, require multiple connections. These applications
may not work with Network Address Translation (NAT) enabled. If you need
to run applications that require multiple connections, use Port Triggering to
specify the additional public ports to be opened for each application.
Alternatively, you can open up a client to unrestricted two-way Internet
access by defining it as DMZ (demilitarized-zone) host.
V
IRTUAL
S
ERVERS
Using the NAT Virtual Server feature, remote users can access different
servers on your local network using your single public IP address.
Remote users accessing services such as web or FTP at your local site
thorugh your public IP address, are redirected (mapped) to other local
server IP addresses and TCP/UDP port numbers. For example, if you set
Type/Public Port to TCP/80 (HTTP or web) and the Private IP/Port to
192.168.7.9/80, then all HTTP requests from outside users forwarded to
192.168.7.9 on port 80. Therefore, by just using your external IP address
provided by your ISP, Internet users can access the services they need at
the local addresses to which you redirect them.
The more common TCP service port numbers include: HTTP: 80, FTP: 21,
Telnet: 23, and POP3: 110. Up to 32 entries can be configured in the
Virtual Servers table.