Nat 1:1 And Nat Loopback Examples - ZyXEL Communications ZyWALL USG 300 User Manual

Chapter 16 Virtual Servers
Table 94 Network > Virtual Server > Edit (continued)
LABEL
Add
corresponding
Policy Route
rule for NAT
Loopback.
Firewall
OK
Cancel

16.3 NAT 1:1 and NAT Loopback Examples

The following sections provide examples of manually configuring NAT 1:1 mapping
and a policy route rule for NAT loopback. These are provided for your reference,
you can select options in the Virtual Server Add/Edit screen to have the
ZyWALL automatically configure these for you instead of configuring them
manually.
NAT 1:1 Example
In this example, there is an SMTP mail server in the LAN zone. It has a private IP
address of 192.168.1.21. The public IP address for the server is 1.1.1.1 and is on
the ge3 interface.
In order for the server to be accessible to people from the Internet (WAN zone),
you need to create a 1:1 NAT mapping from the public IP address to the server's
private one.
302
DESCRIPTION
Select this to allow local users to use a domain name to access this
virtual server. By default this virtual server entry only applies this
address mapping to packets coming in from the WAN.
Or you can click Policy Route to go to the screens where you can
manually configure a NAT loopback policy route for this virtual server.
See page 306 for an example of NAT loopback.
By default the firewall blocks incoming connections from external
addresses. After you configure your virtual server rule settings, click the
Firewall link to configure a firewall rule to allow the virtual server's
traffic to come in.
The ZyWALL checks virtual servers before it applies To-ZyWALL firewall
rules, so To-ZyWALL firewall rules do not apply to traffic that is
forwarded by virtual servers. The ZyWALL still checks other firewall rules
according to the source IP address and mapped IP address.
Click OK to save your changes back to the ZyWALL.
Click Cancel to return to the Virtual Server summary screen without
creating the virtual server (if it is new) or saving any changes (if it
already exists).
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