VMG1312-B Series User’s Guide 185
CHAPTER 11
Network Address Translation (NAT)
11.1 Overview
This chapt er discusses how to configure NAT on the Device. NAT (Network Address Translation -
NAT, RFC 1631) is the t ranslation of t he I P address of a host in a packet, for exam ple, the source
address of an outgoing packet , used wit hin one net work to a different I P address know n within
anot her network.
11.1.1 What You Can Do in this Chapter
• Use the Port For w ar ding screen t o configure forward incom ing service request s t o t he server(s)
on your local network (
Section 11.2 on page 186) .
• Use the Applica t ions screen to forward incom ing service requests t o t he server(s) on your local
net work (Section 11.3 on page 189).
• Use the Por t Trigge ring screen to add and configure t he Device’s t rigger port sett ings (
Section
11.4 on page 190
) .
• Use the DM Z screen to configure a default server (
Section 11.5 on page 193).
• Use the ALG screen t o enable and disable t he NAT and SI P ( VoI P) ALG in the Device (
Section
11.6 on page 194
) .
• Use the Address M apping screen to configure t he Device's address m apping set t ings (
Section
11.7 on page 194
) .
11.1.2 What You Need To Know
Inside/Outside
I nside/ outside denot es where a host is located relative t o the Device, for exam ple, the com puters
of your subscribers are the inside host s, while the web servers on t he I nt ernet are the outside
host s.
Global/Local
Global/ local denotes t he I P address of a host in a packet as t he packet traverses a rout er, for
exam ple, t he local address refers t o t he I P address of a host when t he packet is in the local
net work, while the global address refers t o the I P address of the host when t he sam e packet is
traveling in t he WAN side.
NAT
I n t he sim plest form , NAT changes the source I P address in a packet received from a subscriber
( t he inside local address) to anot her ( t he inside global address) before forwarding t he packet to the
To Next Page
Loading...
