Configuring Cfd; Overview; Basic Cfd Concepts - HPE FlexNetwork HSR6800 series Configuration Manual

Configuring CFD

CFD is supported only when the SAP module is operating in bridge mode.

Overview

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

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 its accuracy. As shown in
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 Router A through Router E, might fail. If a connectivity fault is also detected at the
boundary of MD_B, the failure points might be any of Router B through Router D. If the devices in
MD_B can operate correctly, at least Router C is operational.
Figure 3 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 a VLAN. Packets sent by the MPs in an MA carry the relevant VLAN tag. 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.
Figure
18
3, MD_A in light blue nests