ZyXEL Communications P-660RU-Tx User Manual

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P-660RU-Tx User’s Guide
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Network Address Translation
(NAT)
10.1  Overview
This chapter discusses how to configure NAT on the P-660RU-Tx. 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.
10.1.1  What You Can Do in the NAT Screens
• Use  the  NAT screen (
) to configure the NAT settings.
• Use  the  DMZ screen (
) to configure the DMZ settings.
• Use  the  Virtual Server screen (
) to forward incoming 
service requests to the server(s) on your local network. 
• Use  the  IP Address Mapping screen (
to change your 
P-660RU-Tx’s address mapping settings.
10.1.2  What You Need To Know About NAT
Inside/Outside
Inside/outside denotes where a host is located relative to the P-660RU-Tx, for 
example, the computers of your subscribers are the inside hosts, while the web 
servers on the Internet are the outside hosts. 
Public/Local
Public/local denotes the IP address of a host in a packet as the packet traverses a 
router, for example, the local address refers to the IP address of a host when the 
packet is in the local network, while the public address refers to the IP address of 
the host when the same packet is traveling in the WAN side.