Brocade Multi-Service IronWare Multicast Configuration Guide (Supporting R05.6.00) - Manual (Page 105)

Multi-Service IronWare Multicast Configuration Guide 93
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Configuring DVMRP
1
Grafts to a multicast tree
A DVMRP router restores pruned branches to a multicast tree by sending graft messages towards
the upstream router. Graft messages start at the leaf node and travel up the tree, first sending the
message to its neighbor upstream router.
In the example above, if a new 229.255.0.1 group member joins on router R6, which had been
pruned previously, a graft will be sent upstream to R4. Since the forwarding state for this entry is in
a prune state, R4 sends a graft to R1. Once R4 has joined the tree, it along with R6 will once again
receive multicast packets.
You do not need to perform any configuration to maintain the multicast delivery tree. The prune
and graft messages automatically maintain the tree.
Configuring DVMRP
Enabling DVMRP globally and on an interface
Suppose you want to initiate the use of desktop video for fellow users on a sprawling campus
network. All destination workstations have the appropriate hardware and software but the Brocade
device’s that connect the various buildings need to be configured to support DVMRP multicasts
from the designated video conference server as seen in
Figure 13 .