efm trigger error-down

Usage Scenario

When EFM OAM associated with an interface detects a connectivity fault on a link, the protocol status of the interface goes Down. The interface goes Up after the faulty link recovers.

After the efm trigger error-down command is used, the administrative status of the interface goes Down when EFM OAM detects remote critical-event, dying-gasp, or link-fault events, or local timeout event. Traffic will not be switched back after the faulty link recovers. Check link quality before switching traffic back to the original link.

Prerequisites

EFM OAM has been enabled globally and on an interface using the efm enable command.

Follow-up Procedure

When the protocols status of an interface goes Down because error events are associated with the interface. The protocol status of the interface will not go Up even if the faulty link recovers. In this case, perform either of the following operations:

• Run the restart (interface view) command to restart the interface.

• Run the shutdown (interface view) and undo shutdown (interface view) commands to manually restore the interface.

• Run the undo efm trigger error-down command to disable association between error events and an interface.

To configure the shutdown interface to go Up automatically, run the error-down auto-recovery cause efm-remote-failure interval interval-value command in the system view to enable an interface to go Up and set a recovery delay before the interface enters the error-down state. The interface goes Up automatically after the delay.

Precautions

An interface can be associated with various types of error events. For example, if both efm critical-event trigger error-down and efm dying-gasp trigger error-down are used, the protocol status of the interface becomes Down when the device receives EFM OAM packets indicating critical-event or dying-gasp faults.

• Dying Gasp fault notification function supports models such as Table 1 shows.

  Table 1 Models that support Dying Gasp fault notification

  Product	Model Unless otherwise specified: The models listed in the table can send Dying Gasp messages to the remote device and send Dying Gasp alarms (EFM_1.3.6.1.4.1.2011.5.25.136.1.6.5_hwDot3ahEfmNonThresholdEvent) to the NMS. All interfaces of the device can send Dying Gasp fault notification.
  S2720-EI	All models
  S5720-LI, S5735-L, S5735S-L, S5735S-L-M	All models support except S5720-16X-PWH-LI-AC, S5720-28X-PWH-LI-AC, S5720-52X-PWR-LI-ACF
  S5720S-LI	S5720S-12TP-LI-AC, S5720S-12TP-PWR-LI-AC, S5720S-28TP-PWR-LI-ACL, and S5720S-28X-LI-24S-AC NOTE: They can send Dying Gasp messages to the remote device only, but cannot send Dying Gasp alarms to the NMS. A maximum of 30 interfaces can send Dying Gasp messages.
  S5720I-SI	All models

• The efm critical-event trigger error-down command is used and the remote interface associated with MGR goes Down. The local device will set the protocol status of the corresponding interface to Down after receiving an EFM OAM packet indicating a critical-event fault.

• The efm dying-gasp trigger error-down command is used and the board where the remote interface resides is reset or the system restarts. The local device will set the protocol status of the corresponding interface to Down after receiving an EFM OAM packet indicating a dying-gasp fault.

• The efm link-fault trigger error-down command is used and the physical link of the remote device is faulty. The local device will set the protocol status of the corresponding interface to Down after receiving an EFM OAM packet indicating a link-fault fault.

• The efm timeout trigger error-down command is used on the local device. The local device will set the protocol status of the corresponding interface to Down if it does not receive packets from the remote device in a specified period of time (5s by default).

The efm trigger if-down and efm trigger error-down commands cannot be used simultaneously, and the efm trigger mac-renew and efm trigger error-down commands cannot be used simultaneously.