Ethernet LFM

LFM can be used for physical link-level fault detection and management. The IEEE 802.3ah LFM works across a point-to-point Ethernet link either directly connected or through repeaters.

LFM provides the following functions:

• Failure detection on physical links in both directions, as well as unidirectional failures.
• Ability to put a port in link-loopback mode remotely for diagnostics.
• Report and receive link error events such as framing or symbol errors.

LFM runs at the physical or aggregated interface level. When configured on an aggregated interface, LFM is run individually on each member link. LFM is a link-layer protocol and does not need a Layer 3 (IPv4 or IPv6) address to operate. This allows for LFM to function on circuit cross-connect/transport cross-connect (CCC/TCC) encapsulated interfaces.

The following examples show how LFM is configured in various situations:

• Ethernet LFM Between PE and CE
• Ethernet LFM for CCC
• Ethernet LFM for Aggregated Ethernet
• Ethernet LFM with Loopback Support

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