FEFD State ChangesFEFD has two operational modes, Normal and Aggressive.When you enable Normal mode on an interface and a far-end failure is detected, no intervention is required to reset the interface to bring itback to an FEFD operational state. When you enable Aggressive mode on an interface in the same state, manual intervention is required toreset the interface.FEFD enabled systems (comprised of one or more interfaces) automatically switches between four different states: Idle, Unknown, Bi-directional, and Err-disabled.1 An interface on which FEFD is not configured is in Normal mode by default.2 After you enable FEFD on an interface, it transitions to the Unknown state and sends an FEFD packet to the remote end of the link.3 When the local interface receives the echoed packet from the remote end, the local interface transitions to the Bi-directional state.4 If the FEFD enabled system is configured to use FEFD in Normal mode and neighboring echoes are not received after three intervals,(you can set each interval can be set between 3 and 300 seconds) the state changes to unknown.5 If the FEFD system has been set to Aggressive mode and neighboring echoes are not received after three intervals, the state changesto Err-disabled. You must manually reset all interfaces in the Err-disabled state using the fefd reset [interface] command inEXEC privilege mode (it can be done globally or one interface at a time) before the FEFD enabled system can become operationalagain.Table 49. State Change When Configuring FEFDLocal Event Mode Local State Remote State Local AdminStatus Local ProtocolStatus Remote AdminStatus RemoteProtocolStatusShutdown Normal AdminShutdownUnknown Down Down Up DownShutdown Aggressive AdminShutdownErr-disabled Down Down Up DownFEFD enable Normal Bi-directional Bi-directional Up Up Up UpFEFD enable Aggressive Bi-directional Bi-directional Up Up Up UpFEFD + FEFDdisableNormal Locally disabled Unknown Up Down Up DownFEFD + FEFDdisableAggressive Locally disabled Err-disabled Up Down Up DownLink Failure Normal Unknown Unknown Up Down Up DownLink Failure Aggressive Unknown Unknown Up Down Up DownImportant Points to Remember• FEFD enabled ports are subject to an 8 to 10 second delay during an RPM failover before becoming operational.• You can enable FEFD globally or on a per-interface basis. Interface FEFD configurations override global FEFD configurations.• Dell Networking OS supports FEFD on physical Ethernet interfaces only, excluding the management interface.• FEFD is not supported on Fibre Channel and copper Ethernet ports.528 Layer 2
