beautypg.com

4 nat address mapping, 1 what nat does – ZyXEL Communications NBG410W3G User Manual

Page 232

background image

Chapter 12 Network Address Translation (NAT)

NBG410W3G Series User’s Guide

232

12.4 NAT Address Mapping

Click ADVANCED > NAT > Address Mapping to open the following screen.

12.4.1 What NAT Does

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. Note that the IP address (either local or global) of an outside host is never
changed.
See

Section 12.1 on page 225

for more on NAT.

Use this screen to change your ZyXEL Device’s address mapping settings.

Ordering your rules is important because the ZyXEL Device applies the rules in the order that
you specify. When a rule matches the current packet, the ZyXEL Device takes the
corresponding action and the remaining rules are ignored. If there are any empty rules before
your new configured rule, your configured rule will be pushed up by that number of empty
rules. For example, if you have already configured rules 1 to 6 in your current set and now you
configure rule number 9. In the set summary screen, the new rule will be rule 7, not 9. Now if
you delete rule 4, rules 5 to 7 will be pushed up by 1 rule, so old rules 5, 6 and 7 become new
rules 4, 5 and 6.

Port Forwarding

Rules

The bar displays how many of the ZyXEL Device's possible port forwarding rules are

configured. The first number shows how many port forwarding rules are configured

on the ZyXEL Device. The second number shows the maximum number of port

forwarding rules that can be configured on the ZyXEL Device.

Port Triggering

Rules

The bar displays how many of the ZyXEL Device's possible trigger port rules are

configured. The first number shows how many trigger port rules are configured on

the ZyXEL Device. The second number shows the maximum number of trigger port

rules that can be configured on the ZyXEL Device.

Copy to WAN 2

(and Copy to

WAN 1)

Click Copy to WAN 2 (or Copy to WAN 1) to duplicate this WAN interface's NAT

port forwarding or trigger port rules on the other WAN interface.

Note: Using the copy button overwrites the other WAN interface's

existing rules.

The copy button is best suited for initial NAT configuration where you have

configured NAT port forwarding or trigger port rules for one interface and want to use

similar rules for the other WAN interface. You can use the other NAT screens to edit

the NAT rules after you copy them from one WAN interface to the other.

Apply

Click Apply to save your changes.

Reset

Click Reset to begin configuring this screen afresh.

Table 67 ADVANCED > NAT > NAT Overview (continued)

LABEL

DESCRIPTION