Nat Technical Reference - ZyXEL Communications ZyWALL USG 200 Series User Manual

Table 107 Configuration > Network > NAT > Add (continued)
LABEL
Firewall
OK
Cancel

19.3 NAT Technical Reference

Here is more detailed information about NAT on the ZyWALL.
NAT Loopback
Suppose a NAT 1:1 rule maps a public IP address to the private IP address of a
LAN SMTP e-mail server to give WAN users access. NAT loopback allows other
users to also use the rule's original IP to access the mail server.
ZyWALL USG 100/200 Series User's Guide
DESCRIPTION
By default the firewall blocks incoming connections from external
addresses. After you configure your NAT rule settings, click the Firewall
link to configure a firewall rule to allow the NAT rule's traffic to come in.
The ZyWALL checks NAT rules before it applies To-ZyWALL firewall rules,
so To-ZyWALL firewall rules do not apply to traffic that is forwarded by
NAT rules. 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 NAT summary screen without creating the
NAT rule (if it is new) or saving any changes (if it already exists).
Chapter 19 NAT
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