Nat/Route Mode With Multiple External Network Connections; Transparent Mode - Fortinet FortiGate FortiGate-60M Installation Manual

Getting started

NAT/Route mode with multiple external network connections

Transparent mode

FortiGate-60M Installation Guide
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:
• WAN1 is the default interface to the external network (usually the Internet).
• WAN2 is the redundant interface to the external network. You can also use the
modem interface as a redundant connection to the external network.
• Internal is the interface to the internal network.
You must configure routing to support redundant Internet connections. Routing can be
used to automatically redirect connections from an interface if its connection to the
external network fails.
Otherwise, security policy configuration is similar to a NAT/Route mode configuration
with a single Internet connection. You would create NAT mode firewall policies to
control traffic flowing between the internal, private network and the external, public
network (usually the Internet). If you have multiple internal networks, such as one or
more DMZ networks, in addition to the internal, private network, you can create route
mode firewall policies for traffic flowing between them.
Figure 7: Example NAT/Route multiple internet connection configuration
WAN1
204.23.1.5
Internet
WAN2
64.83.32.45
In Transparent mode, the FortiGate unit is invisible to the network. Similar to a
network bridge, all FortiGate interfaces must be on the same subnet. You only have to
configure a management IP address so that you can make configuration changes.
The management IP address is also used for antivirus and attack definition updates.
You typically use the FortiGate unit in Transparent mode on a private network behind
an existing firewall or behind a router. The FortiGate unit performs firewall functions,
IPSec VPN, virus scanning, IPS, web content filtering, and Spam filtering.
01-28008-0111-20050128
FortiGate-60M Unit
in NAT/Route mode
INTERNAL
PWR STATUS 1 2 3 4 DMZ WAN1 WAN2
LINK 100 LINK 100 LINK 100 LINK 100 LINK 100 LINK 100 LINK 100
Internal
192.168.1.1
NAT mode policies controlling
traffic between internal and
external networks.
Planning the FortiGate configuration
Internal network
192.168.1.3
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