This value configures which Fibre Channel over Ethernet (FCoE) operating mode the switch runs in: non-FCoE, FCF (Fibre Channel Forwarder, acting as a full FC switch), NPV (N-Port Virtualizer, acting as a pass-through), or Transit mode, with the specific rule that the switch can only convert directly between non-FCoE and any one FCoE mode, never directly between two FCoE modes. A storage network administrator sets this when provisioning a switch for converged Ethernet/Fibre-Channel storage traffic, and must remember to step back through non-FCoE mode as an intermediate stage if they need to switch between, say, FCF and NPV modes, since doing so also clears the old mode's FCoE configuration. For example, an administrator moving a switch from FCF mode to NPV mode would first set this to non-FCoE(1), then set it to npv(3), rather than attempting to go straight from FCF to NPV.