In Transparent mode, your FortiGate unit becomes a Layer-2 bridge — any traffic coming in on one port is broadcast out on all the other ports. If your FortiGate unit has many interfaces, this is not the best use of those interfaces. VDOMs can limit Transparent mode to only a few interfaces while allowing the rest of the FortiGate unit to remain in NAT/Route mode.

The essential steps to configure your FortiGate unit to work with VLANs in Transparent mode are:

You can also configure the security profiles that manage antivirus scanning, web filtering and spam filtering.

In Transparent mode, you can access the FortiGate web-based manager by connecting to an interface configured for administrative access and using HTTPS to access the management IP address. On the FortiGate unit used for examples in this guide, administrative access is enabled by default on the internal interface and the default management IP address is 10.11.0.1.