Fortinet FortiGate FortiGate-3016B - Nat;Route Mode with Multiple External Network Connections

FortiGate-3016B, FortiGate-3600A and FortiGate-3810A FortiOS 3.0 MR5 Install Guide
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Planning the FortiGate configuration Configuring
Figure 4: Example NAT/Route mode configuration.
NAT/Route mode with multiple external network connections
In NAT/Route mode, you can configure the FortiGate unit with multiple redundant
connections to the external network (usually the Internet).
For example, you could create the following configuration:
• Port 1 is the default interface to the external network (usually the Internet)
• Port 2 is the internal interface to the internal network
• Port 3 is the redundant interface to the external network
You must configure routing to support redundant Internet connections. Routing
can automatically redirect connections from an interface if its connection to the
external network fails.
Otherwise, security policy configurations is similar to a NAT/Route mode
configuration with a single Internet connection. You would create NAT mode
firewall policies to control traffic following between the internal, private network
and the external, public network (usually the Internet).
FortiGate-3600A
Internet
DMZ
network
Port 3
Internal
network
Port2
Route mode policies
controlling traffic between
Internal networks.
NAT policies controlling
traffic between internal
and external networks.
Port1
Note: If you have multiple networks, such as a DMZ network in addition to the internal
private network, you could create route mode firewall policies for traffic flowing between
them.