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Section 4 Configure
Typical Network Diagram
A typical network utilizing the NAT Default Server looks like this:
NAT Combination Application
Cayman’s NAT security feature allows you to configure a sophisticated LAN
layout that uses both the Pinhole and Default Server capabilities.
With this topology, you configure the embedded administration ports as a
first task, followed by the Pinholes and, finally, the NAT Default Server.
When using both NAT pinholes and NAT Default Server the Gateway works
with the following rules (in sequence) to forward traffic from the Internet
to the LAN:
1. If the packet is a response to an existing connection created by outbound traf-
fic from a LAN PC, forward to that station.
2. If not, check for a match with a pinhole configuration and, if one is found, for-
ward the packet according to the pinhole rule.
3. If there’s no pinhole, the packet is forwarded to the Default Server.
WAN
LAN
Ethernet
Interface
192.168.1.3
192.168.1.2
192.168.1.1
LAN STN #3
LAN STN #2
NAT Default Server
Gateway
NAT
NAT Pinhole
Embedded
Web Server
210.219.41.20
210.219.41.20
(Port 80 default)
NAT protected
Ethernet
Interface
Internet