Pim-Dm Configuration - Huawei Quidway S3500 Series Operation Manual

Operation Manual - Multicast
Quidway S3500 Series Ethernet Switches
specified unicast routing protocol such as the routing information learned by RIP and
OSPF
III. Assert mechanism
As shown in the following figure, both routers A and B on the LAN have their own
receiving paths to multicast source S. In this case, when they receive a multicast packet
sent from multicast source S, they will both forward the packet to the LAN. Multicast
Router C at the downstream node will receive two copies of the same multicast packet.
Router A
Figure 6-1 Assert mechanism diagram
When they detect such a case, routers need to select a unique sender by using the
assert mechanism. Routers will send Assert packets to select the best path. If two or
more than two paths have the same priority and metric, the path with a higher IP
address will be the upstream neighbor of the (S, G) entry, which is responsible for
forwarding the (S, G) multicast packet.
IV. Graft
When the pruned downstream node needs to be restored to the forwarding state, the
node will send a graft packet to inform the upstream node.

6.1 PIM-DM Configuration

When the router runs in the PIM-DM domain, it is recommended to enable PIM-DM on
all the interfaces of the non-border router.
Basic configuration of PIM-DM include:
Enabling multicast
Enabling PIM-DM protocol
Advanced configuration of PIM-DM include:
Configuring the interval of Hello messages
Entering PIM view
Multicast packets forwarded by the
upstream node
Router C
Huawei Technologies Proprietary
6-2
Chapter 6 PIM-DM Configuration
Router B
Receiver