Brocade BigIron RX Series Configuration Guide - Manual (Page 801)

BigIron RX Series Configuration Guide 723
53-1002484-04
DVMRP overview
24
FIGURE 107 Pruning leaf nodes from a multicast tree
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.
...
... ...
229.225.0.1
Group
Member Group
Member
Video Conferencing
Server
(207.95.5.1, 229.225.0.1)
(Source, Group)
229.225.0.1
Group
Member Group
Member Group
Member
Group
Member Group
Member Group
Member
229.225.0.1
Leaf Node
(No Group Members)
Intermediate Node
(No Group Members)
R2 R1
R3
R4
R5
R6
Prune Message
sent to upstream router (R4)