HP 6125G HP 6125G & 6125G/XG Blade Switches IP Multicast Configuration - Page 276

MLD proxying, Protocols and standards, Network diagram

Page 276 highlights

MLD proxying In some simple tree-shaped topologies, you do not need to configure complex IPv6 multicast routing protocols, such as IPv6 PIM, on the boundary devices. Instead, you can configure MLD proxying on these devices. With MLD proxying configured, the device serves as a proxy for the downstream hosts to send MLD messages, maintain group memberships, and implement IPv6 multicast forwarding based on the memberships. In this case, the MLD proxy device is a host but no longer an IPv6 PIM neighbor to the upstream device. Figure 77 Network diagram As shown in Figure 77, an MLD proxy device has the following types of interfaces: • Upstream interface-Also called the "proxy interface." A proxy interface is an interface on which MLD proxying is configured. It is in the direction toward the root of the multicast forwarding tree. An upstream interface acts as a host that is running MLD, and is also called a "host interface." • Downstream interface-An interface that is running MLD and not in the direction toward the root of the multicast forwarding tree. A downstream interface acts as a router that is running MLD, and is also called a "router interface." A device with MLD proxying configured maintains a group membership database, which stores the group memberships on all the downstream interfaces in this database. Each entry comprises the multicast address, filter mode, and source list. Such an entry is a collection of members in the same multicast group on each downstream interface. A proxy device performs host functions on the upstream interface based on the database. It responds to the queries according to the information in the database or sends join/leave messages when the database changes. The proxy device performs router functions on the downstream interfaces by participating in the querier election, sending queries, and maintaining memberships based on the reports. Protocols and standards • RFC 2710, Multicast Listener Discovery (MLD) for IPv6 • RFC 3810, Multicast Listener Discovery Version 2 (MLDv2) for IPv6 265

  • 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
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
  • 218
  • 219
  • 220
  • 221
  • 222
  • 223
  • 224
  • 225
  • 226
  • 227
  • 228
  • 229
  • 230
  • 231
  • 232
  • 233
  • 234
  • 235
  • 236
  • 237
  • 238
  • 239
  • 240
  • 241
  • 242
  • 243
  • 244
  • 245
  • 246
  • 247
  • 248
  • 249
  • 250
  • 251
  • 252
  • 253
  • 254
  • 255
  • 256
  • 257
  • 258
  • 259
  • 260
  • 261
  • 262
  • 263
  • 264
  • 265
  • 266
  • 267
  • 268
  • 269
  • 270
  • 271
  • 272
  • 273
  • 274
  • 275
  • 276
  • 277
  • 278
  • 279
  • 280
  • 281
  • 282
  • 283
  • 284
  • 285
  • 286
  • 287
  • 288
  • 289
  • 290
  • 291
  • 292
  • 293
  • 294
  • 295
  • 296
  • 297
  • 298
  • 299
  • 300
  • 301
  • 302
  • 303
  • 304
  • 305
  • 306
  • 307
  • 308
  • 309
  • 310
  • 311
  • 312
  • 313
  • 314
  • 315
  • 316
  • 317
  • 318
  • 319
  • 320
  • 321
  • 322
  • 323
  • 324
  • 325
  • 326
  • 327
  • 328
  • 329
  • 330
  • 331
  • 332
  • 333
  • 334
  • 335
  • 336
  • 337
  • 338
  • 339
  • 340
  • 341
  • 342
  • 343
  • 344
  • 345
  • 346
  • 347
  • 348
  • 349
  • 350
  • 351
  • 352
  • 353
  • 354
  • 355
  • 356
  • 357
  • 358
  • 359
  • 360
  • 361
  • 362
  • 363
  • 364
  • 365
  • 366
  • 367
  • 368
  • 369
  • 370
  • 371
  • 372
  • 373
  • 374
  • 375
  • 376
  • 377
  • 378
  • 379

265
MLD proxying
In some simple tree-shaped topologies, you do not need to configure complex IPv6 multicast routing
protocols, such as IPv6 PIM, on the boundary devices. Instead, you can configure MLD proxying on these
devices. With MLD proxying configured, the device serves as a proxy for the downstream hosts to send
MLD messages, maintain group memberships, and implement IPv6 multicast forwarding based on the
memberships. In this case, the MLD proxy device is a host but no longer an IPv6 PIM neighbor to the
upstream device.
Figure 77
Network diagram
As shown in
Figure 77
, an MLD proxy device has the following types of interfaces:
Upstream interface
—Also called the "proxy interface." A proxy interface is an interface on which
MLD proxying is configured. It is in the direction toward the root of the multicast forwarding tree. An
upstream interface acts as a host that is running MLD, and is also called a "host interface."
Downstream interface
—An interface that is running MLD and not in the direction toward the root of
the multicast forwarding tree. A downstream interface acts as a router that is running MLD, and is
also called a "router interface."
A device with MLD proxying configured maintains a group membership database, which stores the
group memberships on all the downstream interfaces in this database. Each entry comprises the multicast
address, filter mode, and source list. Such an entry is a collection of members in the same multicast group
on each downstream interface.
A proxy device performs host functions on the upstream interface based on the database. It responds to
the queries according to the information in the database or sends join/leave messages when the
database changes. The proxy device performs router functions on the downstream interfaces by
participating in the querier election, sending queries, and maintaining memberships based on the
reports.
Protocols and standards
RFC 2710,
Multicast Listener Discovery (MLD) for IPv6
RFC 3810,
Multicast Listener Discovery Version 2 (MLDv2) for IPv6