Network Address Translation (Nat) Screens; Nat Overview; Nat Virtual Servers - ZyXEL Communications P-663HN-51 User Manual

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H A P T E R
Network Address Translation
This chapter discusses how to configure NAT on the ZyXEL Device.

7.1 NAT Overview

NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP
address of a host in a packet, for example, the source address of an outgoing
packet, used within one network to a different IP address known within another
network.

7.2 NAT Virtual Servers

Configure NAT virtual server (port forwarding) entries to have the ZyXEL Device
forward traffic from the WAN to LAN computers.
You might do this to get particular games or services to work through NAT. You
can also make servers, for example, web or FTP, visible to the outside world even
though NAT makes your whole inside network appear as a single computer to the
outside world.
You may enter a single port number or a range of port numbers to be forwarded,
and the local IP address of the desired server. The port number identifies a
service; for example, web service is on port 80 and FTP on port 21. In some
cases, such as for unknown services or where one server can support more than
one service (for example both FTP and web service), it might be better to specify
a range of port numbers. You can allocate a server IP address that corresponds to
a port or a range of ports.
Many residential broadband ISP accounts do not allow you to run any server
processes (such as a Web or FTP server) from your location. Your ISP may
P-663HN-51 User's Guide
(NAT) Screens
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