11 configuring cfm, 1 overview, 2 references – CANOGA PERKINS 9175 Configuration Guide User Manual

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CanogaOS Configuration Guide

11-1

11 Configuring CFM

This chapter contains a complete sample Connectivity Fault Management (CFM)
Protocol configuration. To see details on the commands used in this example, or to see
the outputs of the validation commands, refer to the OAM Command Reference. To
avoid repetition, some Common commands, like configure terminal, have not been listed
under the Commands Used section.

11.1 Overview

The main functions of Ethernet to the First Mile - Operation Administration and
Maintenance (EFM-OAM) are link performance monitoring, fault detection, fault signaling
and loopback signaling. OAM information is conveyed in Slow Protocol frames called
OAM Protocol Data Units (OAMPDUs). OAMPDUs contain the appropriate control and
status information used to monitor, test and troubleshoot OAM-enabled links.
Connectivity Fault Management provides the capability to detect, verify, isolate and
notify connectivity failures on a Virtual Bridged LAN based on the protocol standard
specified in IEEE 802.1ag d-6-0. It provides for discovery and verification of paths
through 802.1 bridges and LANs, and is part of the enhanced Operation, Administration
and Management (OAM) features .CFM is designed to be transparent to the customer
data transported by a network and to be capable of providing maximum fault coverage.
CFM uses standard Ethernet frames distinguished by EtherType. These CFM messages
are supported:

• Continuity Check messages (CC)

• Loopback

messages

• Linktrace

messages


Continuity Check (CC) messages
Multicast heartbeat messages exchanged periodically between MEPs that allow MEPs
to discover other MEPs within a domain and allow MIPs to discover MEPs. CC
messages are configured to a domain or VLAN.

Loopback messages
Unicast frames transmitted by a MEP at administrator request to verify connectivity to a
particular maintenance point, indicating if a destination is reachable. A loopback
message is similar to an Internet Control Message Protocol (ICMP) ping message.

Linktrace messages
Multicast frames transmitted by a MEP at administrator request to track the path
(hop-by-hop) to a destination MEP. Traceroute messages are similar in concept to UDP
traceroute messages.

11.2 References

IEEE 802.1ag/D8.1

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