Configuring Ip Multicast Routing - Cisco ONS 15454 SDH Configuration Manual

Configuring IP Multicast Routing

PIM dense mode assumes that the downstream networks want to receive the datagrams forwarded to
them. The ML-Series card forwards all packets on all outgoing interfaces until pruning and truncating
occur. Interfaces that have PIM dense mode enabled receive the multicast data stream until it times out.
PIM dense mode is most useful under these conditions:
•
•
•
PIM sparse mode assumes that the downstream networks do not want to forward multicast packets for a
group unless there is an explicit request for the traffic. PIM sparse mode defines a rendezvous point,
which is used as a registration point to facilitate the proper routing of packets.
When a sender wants to send data, it first sends the data to the rendezvous point. When a ML-Series card
is ready to receive data, it registers with the rendezvous point. After the data stream begins to flow from
the sender to the rendezvous point and then to the receiver, ML-Series cards in the data path optimize
the path by automatically removing any unnecessary hops, including the rendezvous point.
PIM sparse mode is optimized for environments in which there are many multipoint data streams and
each multicast stream goes to a relatively small number of LANs in the internetwork. PIM sparse mode
is most useful under these conditions:
•
•
•
The ML-Series card support Reverse Path Forwarding (RPF) multicast, but not RPF unicast.
Note
Configuring IP Multicast Routing
To configure IP multicast routing, perform the following procedure, beginning in global configuration
mode:
Command
Step 1
Router(config)# ip multicast-routing
Step 2
Router(config)# interface type number
Step 3
Router(config-if)# ip pim
sparse mode
Step 4
Router(config)# ip pim rp-address
rendezvous-point ip-address
Step 5
Router(config-if)# end
Step 6
Router# copy running-config startup-config
Cisco ONS 15454 and Cisco ONS 15454 SDH Ethernet Card Software Feature and Configuration Guide, R8.0
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When senders and receivers are in close proximity to each other
When the internetwork has fewer senders than receivers
When the stream of multicast traffic is constant
When there are few receivers in the group
When senders and receivers are separated by WAN links
When the stream of multicast traffic is intermittent
{
|
sparse-dense-mode
Purpose
Enables IP multicasting on the ML-Series card.
Enters interface configuration mode to configure
any interface.
|
Runs IP multicast routing on each interface on
dense-mode
}
which you enter this command. You must indicate
dense mode, sparse mode, or sparse-dense mode.
Configures a rendezvous point for the multicast
group.
Returns to privileged EXEC mode.
(Optional) Saves your configuration changes to
NVRAM.
Chapter 11 Configuring Networking Protocols