CANOGA PERKINS CanogaOS Configuration Guide - Manual (Page 181)

CanogaOS Configuration Guide
Proprietary & Confidential Canoga Perkins Metro Ethernet Switches Page 181 of 350
When the RP detects the normal multicast packets, it sends a Register-Stop message to the
source DR, meaning it should stop sending register packets.
6. Sending Register-Stop Messages
When the RP begins receiving traffic from the source, both as Register messages and as
unencapsulated IP packets, it sends a Register-Stop message to the DR. This notifies the DR that
the traffic is now being received as standard IP multicast packets on the SPT. When the DR
receives this message, it stops encapsulating traffic in Register messages.
7. Pruning the Interface
Routers attached to receivers send Prune messages to the RP to disassociate the source from the
RP. When an RP receives a Prune message, it no longer forwards traffic from the source
indicated in the Prune message. If all members of a multicast group are pruned, the IGMP state
of the DR is deleted, and the interface is removed from the Source and Group lists of the group.
8. Forwarding Multicast Packets
PIM-SM routers forward multicast traffic onto all interfaces that lead to receivers that have
explicitly joined a multicast group. Messages are sent to a group address in the local subnetwork,
and have a Time to Live (TTL) of 1. The router performs an RPF check, and forwards the
packet. Traffic that arrives on the correct interface is sent onto all outgoing interfaces that lead to
downstream receivers if the downstream router has sent a join to this router, or is a member of
this group.
24.3.4 PIM-SM Configuration
PIM-SM is a soft-state protocol. The main requirement is to enable PIM-SM on desired
interfaces, and configure the RP information correctly, through static or dynamic methods. All
multicast group states are maintained dynamically as the result of IGMP Report/Leave and PIM
Join/Prune messages. Currently, we supports only one RP for all multicast groups (224.0.0.0/4).
This section provides PIM-SM configuration examples for two relevant scenarios. The following
graphic displays the network topology used in these examples:
Configuring RP statically
In this example, using the above topology, Router_C is the Rendezvous Point (RP), and all
routers are statically configured with RP information. Host_1 and Host_2 join group 224.0.1.3
for all the sources. They send IGMP membership report to Subnet 1. Two routers are attached to
Subnet 1--Router_E and Router_F; both have default DR priority on eth-0-1. The Router_E
having a higher IP address on the eth-0-1 becomes the Designated Router (DR), and is
responsible for sending Join messages to the RP (Router_C). While configuring the RP, make
sure that:
• Every router includes the ip pim rp-address 10.10.1.5 statement, even if it does not have any
source or group member attached to it.
• There is only one RP address for a group scope in the PIM domain.