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Handbook

VLAN trunking and MAC address learning

6.0.0
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VLAN trunking and MAC address learning

A FortiGate port becomes a trunk when 2 or more VLANs are configured on this port, in the same or different forwarding domains.

When trunks are configured on a FortiGate, it is essential to create forward domains, in order to avoid packets looping back on the VLANs of the trunk. This will confine all broadcasts and multicast traffic between the interfaces belonging to a same forward domain.

In the case where a trunk port is configured with a VLAN in a different forwarding domains, the MAC address of the network device connected to this port learns the FDB of each forwarding domain. This is Independent VLAN Learning (IVL).

VLAN trunking and MAC address learning

A FortiGate port becomes a trunk when 2 or more VLANs are configured on this port, in the same or different forwarding domains.

When trunks are configured on a FortiGate, it is essential to create forward domains, in order to avoid packets looping back on the VLANs of the trunk. This will confine all broadcasts and multicast traffic between the interfaces belonging to a same forward domain.

In the case where a trunk port is configured with a VLAN in a different forwarding domains, the MAC address of the network device connected to this port learns the FDB of each forwarding domain. This is Independent VLAN Learning (IVL).