ZyXEL Communications P-870HW-51A V2, Руководство пользователя

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P-870HW-51a v2 User’s Guide
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H A P T E R
8
Network Address Translation
(NAT)
8.1 Overview
This chapter discusses how to configure NAT on the ZyXEL Device.
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.
8.1.1 What You Can Do in this Chapter
The Port Forwarding screen lets you configure forward incoming service requests to the
server(s) on your local network ( Section 8.3 on page 99 ).
8.2 What You Need to Know
The following terms and concepts may help as you read through this chapter.
NAT
In the simplest form, NAT changes the source IP address in a packet received from a
subscriber (the inside local address) to another (the inside global address) before forwarding
the packet to the WAN side. When the response comes back, NAT translates the destination
address (the inside global address) back to the inside local address before forwarding it to the
original inside host.
Port Forwarding
A port forwarding set is a list of inside (behind NAT on the LAN) servers, for example, web or
FTP, that you can make visible to the outside world even though NAT makes your whole
inside network appear as a single computer to the outside world.
8.3 The Port Forwarding Screen
This summary screen provides a summary of all port forwarding rules and their configuration.
In addition, this screen allows you to create new port forwarding rules and delete existing
rules.