Dell MX9116n EMC SmartFabric OS10 User Guide - Page 367

FEFD modes FEFD operates in two modes-Normal mode and aggressive mode. • Normal mode-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 it back to an FEFD operational state. • Aggressive mode-When you enable Aggressive mode on an interface in the same state, you must manually reset the interface. The following events explain how FEFD state transition occurs: • When you enable FEFD on an interface a link transitions from idle state to unknown state. • In the unknown state, the interface starts transmitting link state information at a regular interval. The interface state changes to bi- directional when a handshake is complete with the peer. • When an interface is in bi-directional state, if it does not receive an echo from its peer for the time interval of three times the configured FEFD message interval, the interface state changes to unknown in Normal mode. In Aggressive mode, the interface state changes to err-disabled. If the interface state changes to err-disabled, use the fefd reset [interface] global command to reset these interfaces. The unknown or err-disabled state brings the line protocol down so that the protocols above it can detect that the peer link is down. Table 30. FEFD state changes Local event Configured (User FEFD mode intervention) Local state (Show display) (Result) Local admin State (Result) Local line protocol Status (Result) Remote state (Show display) (Result) Remote admin state Remote line protocol status Shutdown(user Normal configuration) Admin Shutdown Down Down Line protocol is Up down. Down Shutdown(user Aggressive configuration) Admin Shutdown Down Down Line protocol is Up down. Down FEFD+ FEFD Normal Locally disabled Up Up Unknown Up Down disable(user configuration) FEFD + FEFD disable(user configuration) Aggressive Locally disabled Up Down Err-disabled Up Down Link Failure Normal (Remove cable or transceiver) Unknown Up Down Unknown Up Down Link Aggressive Unknown Up Failure(Remov e cable or transceiver) Down Unknown Up Down FEFD Normal Bi-directional Up Up Bi-directional Up Up enable(user configuration) FEFD Aggressive Bi-directional Up Up Bi-directional Up Up enable(user configuration) Restrictions • You can enable FEFD globally or on an interface. If FEFD is enabled globally, the FEFD interface configuration overrides global FEFD configuration. • OS10 supports FEFD only on physical interfaces. FEFD is not supported on any other interfaces. However, you can enable FEFD on individual physical interfaces that belong to a port channel. Layer 2 367