To use Fibre Channel over Ethernet (FCoE), you need to install FCoE adapters on your host.
The adapters that VMware supports generally fall into two categories, hardware FCoE adapters and software FCoE adapters that use the native FCoE stack in ESXi.
Hardware FCoE Adapters
This category includes completely offloaded specialized Converged Network Adapters (CNAs) that contain network and Fibre Channel functionalities on the same card.
When such adapter is installed, your host detects and can use both CNA components. In the client, the networking component appears as a standard network adapter (vmnic) and the Fibre Channel component as a FCoE adapter (vmhba). You do not need to configure the hardware FCoE adapter to be able to use it.
Software FCoE Adapters
A software FCoE adapter uses the native FCoE protocol stack in ESXi for the protocol processing. The software FCoE adapter is used with a NIC that offers Data Center Bridging (DCB) and I/O offload capabilities. Intel X520 is an example of such NIC. For information on NICs supporting software FCoE, see the vSphere Compatibility Guide.
For the software FCoE adapter, you must properly configure networking and then activate the adapter.
The number of software FCoE adapters you activate corresponds to the number of physical NIC ports. ESXi supports a maximum of four software FCoE adapters on one host.