Chapter 10 Network Address Translation (NAT)
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.
Single IP Versus NAT
Single IP is a ZyNOS implementation of a subset of NAT that supports two types of mapping,
•Choose Single IP if you have just one public WAN IP address for your ZyXEL Device.
•Choose Multiple IPs if you have multiple public WAN IP addresses for your ZyXEL Device.
Finding Out More
See Section 10.6 on page 88 for advanced technical information on NAT.
10.2 The NAT Screen
Use this screen to configure NAT for each PVC. Click Advanced Setup > NAT to open the following screen.
Figure 34 Advanced Setup > NAT
The following table describes the labels in this screen.
Table 21 Network > NAT > General
LABEL | DESCRIPTION |
Virtual Circuit | Select the PVC you want to configure from the |
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NAT Status | This field shows whether NAT is enabled. See Section 7.2 on page 55 for more |
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