Technical Reference - ZyXEL Communications NXC5200 User Manual

Chapter 14 NAT
Table 78 Configuration > Network > NAT > Add/Edit (continued)
LABEL
Firewall
OK
Cancel

14.3 Technical Reference

The following section contains additional technical information about the features
described in this chapter.
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.
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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 NXC checks NAT rules before it applies To-NXC firewall rules, so To-
NXC firewall rules do not apply to traffic that is forwarded by NAT rules.
The NXC still checks other firewall rules according to the source IP
address and mapped IP address.
Click OK to save your changes back to the NXC.
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).
NXC5200 User's Guide