Configuring Cfd; Overview; Basic Cfd Concepts - HPE FlexFabric 5700 Series Configuration Manual

Configuring CFD

Overview

Connectivity Fault Detection (CFD), which conforms to IEEE 802.1ag Connectivity Fault
Management (CFM) and ITU-T Y.1731, is an end-to-end per-VLAN link layer OAM mechanism. CFD
is used for link connectivity detection, fault verification, and fault location.

Basic CFD concepts

Maintenance domain
A maintenance domain (MD) defines the network or part of the network where CFD plays its role. An
MD is identified by its 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
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, might fail. If a connectivity fault is also
detected at the boundary of MD_B, the failure points can be any of Device B through Device D. If the
devices in MD_B can operate correctly, at least Device C is operational.
Figure 2 Two nested MDs
CFD exchanges messages and performs operations on a per-domain basis. By planning MDs
correctly in a network, you can use CFD to rapidly locate failure points.
Maintenance association
A maintenance association (MA) is a part of an MD. You can configure multiple MAs in an MD as
needed. An MA is identified by the MD name + MA name.
An MA serves the specified VLAN or no VLAN. An MA that serves a VLAN is considered to be
carrying VLAN attribute. An MA that serves no VLAN is considered to be carrying no VLAN attribute.
An MP can receive packets sent by other MPs in the same MA. The level of an MA equals the level of
the MD that the MA belongs to.
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Figure 2, MD_A