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CFD Configuration
When configuring CFD, go to these sections for information you are interested in:
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Displaying and Maintaining CFD
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Overview
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
Maintenance domain
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 MD name.
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
,
MD_A 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.
