3com S7906E インストール手順
1-1
1
Connectivity Fault Detection Configuration
When configuring CFD, go to these sections for information you are interested in:
z
z
z
z
z
z
z
z
The S7900E Series Ethernet Switches are distributed devices that support Intelligent Resilient
Framework (IRF). Two S7900E series can be connected together to form a distributed IRF device. For
introduction of IRF, refer to IRF Configuration in the System Volume.
Overview
Connectivity Fault Detection (CFD) 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 locate faults exactly, 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.