When configuring CFD, go to these sections for information you are interested in:
CFD Configuration Task List
Basic Configuration Tasks
Configuring CC on MEPs
Configuring LB on MEPs
Configuring LT on MEPs
Displaying and Maintaining CFD
CFD Configuration Examples
Connectivity Fault Detection (CFD), which conforms to Connectivity Fault Management (CFM) defined
by IEEE 802.1ag, is an end-to-end per-VLAN link layer Operations, Administration and Maintenance
(OAM) mechanism used for link connectivity detection, fault verification, and fault location.
Basic Concepts in CFD
A maintenance domain (MD) defines the network where CFD plays its role. The MD boundary is defined
by some maintenance association end points (MEPs) configured on the ports. An MD is identified by an
To accurately locate faults, CFD introduces eight levels (from 0 to 7) to MDs. The bigger the number, the
higher the level and the larger the area covered. Domains can touch or nest (if the outer domain has a
higher level than the nested one) but cannot intersect or overlap.
MD levels facilitate fault location and make fault location more accurate. As shown in
in light blue nests MD_B in dark blue. If a connectivity fault is detected at the boundary of MD_A, any of
the devices in MD_A, including Device A through Device E, may fail. In this case, if a connectivity fault is
also detected at the boundary of MD_B, the failure points may be any of Device B through Device D. If
the devices in MD_B operate normally, you can be sure that at least Device C is operational.