HP 6125XLG R2306-HP 6125XLG Blade Switch High Availability Configuration Guide - Page 18

Configuring CFD, Overview, Basic CFD concepts, Maintenance domain, Maintenance association

Page 18 highlights

Configuring CFD Overview Connectivity Fault Detection (CFD), which conforms to IEEE 802.1ag Connectivity Fault Management (CFM), is an end-to-end per-VLAN link layer OAM mechanism 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 Figure 2, 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, 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 properly 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". 13

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144

13
Configuring CFD
Overview
Connectivity Fault Detection (CFD), which conforms to IEEE 802.1ag Connectivity Fault Management
(CFM), is an end-to-end per-VLAN link layer OAM mechanism 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
Figure 2
, 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, 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 properly
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".