Transparent Mode - Fortinet FortiGate FortiGate-100 Installation Manual

Getting started

Transparent mode

FortiGate-100 Installation Guide
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 a DMZ
network, in addition to the internal, private network, you can create route mode firewall
policies for traffic flowing between them.
Figure 6: Example NAT/Route multiple internet connection configuration
External
204.23.1.5
Internet
DMZ
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.
Figure 7: Example Transparent mode network configuration
Gateway to
public network
204.23.1.5 192.168.1.1
Internet
(firewall, router)
You can connect up to three network segments to the FortiGate unit to control traffic
between these network segments.
• External can connect to the external firewall or router.
• Internal can connect to the internal network.
• DMZ can connect to another network segment.
01-28004-0019-20040830
FortiGate-100 Unit
in NAT/Route mode
POWER
INTERNAL EXTERNAL DMZ
STATUS
Internal
192.168.1.1
NAT mode policies controlling
traffic between internal and
external networks.
FortiGate-100 Unit
in Transparent mode
INTERNAL EXTERNAL DMZ
External
192.168.1.2
Management IP
Transparent mode policies
controlling traffic between
internal and external networks
Transparent mode
Internal network
Internal network
POWER
STATUS
Internal
192.168.1.3
192.168.1.3
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