Cisco Cisco IOS Software Release 12.2(33)SRE

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Ethernet Connectivity Fault Management (CFM) is an end-to-end per-service-instance Ethernet layer 
operation, administration, and management (OAM) protocol. It includes proactive connectivity 
monitoring, fault verification, and fault isolation for large Ethernet metropolitan-area networks (MANs) 
and WANs.

The advent of Ethernet as a MAN and WAN technology imposes a new set of OAM requirements on 
Ethernet’s traditional operations, which were centered on enterprise networks only. The expansion of 
Ethernet technology into the domain of service providers, where networks are substantially larger and 
more complex than enterprise networks and the user base is wider, makes operational management of 
link uptime crucial. More importantly, the timeliness in isolating and responding to a failure becomes 
mandatory for normal day-to-day operations, and OAM translates directly to the competitiveness of the 
service provider. 

Your Cisco IOS software release may not support all of the features documented in this module. To reach 
links to specific feature documentation in this module and to see a list of the releases in which each feature is 
supported, use the 

.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS 
software image support. To access Cisco Feature Navigator, go to

. An 

account on Cisco.com is not required.