Configuring LT

LT can trace the path between source and target MEPs, and can locate link faults by automatically sending LT messages. The two functions are implemented in the following way:

• Tracing path—The source MEP first sends LTM messages to the target MEP. Based on the LTR messages in response to the LTM messages, the path between the two MEPs is identified.

• LT messages automatic sending—If the source MEP fails to receive CCM frames from the target MEP within 3.5 times the transmission interval, it considers the link faulty. The source MEP then sends LTM frames, with the TTL field set to the maximum value 255, to the target MEP. Based on the returned LTRs, the fault source is located.

Before you configure LT on a MEP in an MA carrying VLAN attribute, create the VLAN to which the MA belongs.

1. Identify the path between a source MEP and a target MEP.

   cfd linktrace service-instance instance-id mep mep-id { target-mac mac-address | target-mep target-mep-id } [ ttl ttl-value ] [ hw-only ]

   This command is available in any view.

2. Enter system view.

   system-view

3. Enable LT messages automatic sending.

   cfd linktrace auto-detection [ size size-value ]

   By default, LT messages automatic sending is disabled.