Nat Address Mapping; What Nat Does - ZyXEL Communications NBG410W3G User Manual

Chapter 12 Network Address Translation (NAT)
Table 67 ADVANCED > NAT > NAT Overview (continued)
LABEL
Port Forwarding
Rules
Port Triggering
Rules
Copy to WAN 2
(and Copy to
WAN 1)
Apply
Reset

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
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.
232
DESCRIPTION
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.
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.
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.
Click Apply to save your changes.
Click Reset to begin configuring this screen afresh.
for more on NAT.
NBG410W3G Series User's Guide