33-17
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 33 Configuring IP Multicast Configuring IP Multicast Routing
For an example of how to configure bidir-PIM, see the “Bidirectional PIM Mode Example” section on
page 33-29.
Enabling PIM-SSM Mapping
The Catalyst 4500 series switch supports SSM mapping, enabling an SSM transition in cases either
where neither URD nor IGMP v3-lite is available, or when supporting SSM on the end system is
impossible or unwanted due to administrative or technical reasons. With SSM mapping, you can leverage
SSM for video delivery to legacy set-top boxes (STBs) that do not support IGMPv3 or for applications
that do not take advantage of the IGMPv3 host stack.
For more details, refer to this URL:
http://www.cisco.com/en/US/docs/ios-xml/ios/ipmulti_igmp/configuration/15-s/imc_ssm_map.html
Configuring a Rendezvous Point
A rendezvous point (RP) is required in networks running Protocol Independent Multicast sparse mode
(PIM-SM). In PIM-SM, traffic is forwarded only to network segments with active receivers that have
explicitly requested multicast data.
The most commonly used methods to configure a rendezvous point (described here) are the use of Static
RP and the use of the Auto-RP protocol. Another method (not described here) is the use of the Bootstrap
Router (BSR) protocol.

Configuring Auto-RP

Auto-rendezvous point (Auto-RP) automates the distribution of group-to-rendezvous point (RP)
mappings in a PIM network. To make Auto-RP work, a router must be designated as an RP mapping
agent, which receives the RP announcement messages from the RPs and arbitrates conflicts. The RP
mapping agent then sends the consistent group-to-RP mappings to all other routers by way of dense
mode flooding.
All routers automatically discover which RP to use for the groups they support. The Internet Assigned
Numbers Authority (IANA) has assigned two group addresses, 224.0.1.39 and 224.0.1.40, for Auto-RP.
The mapping agent receives announcements of intention to become the RP from Candidate-RPs. The
mapping agent then announces the winner of the RP election. This announcement is made independently
of the decisions by the other mapping agents.
To configure a rendezvous point, perform this task:
Command or Action Purpose
Step 1 Switch> enable Enables privileged EXEC mode.
Step 2 Switch# configure terminal Enters global configuration mode.
Step 3 Switch(config)# ip multicast-routing Enables IP multicast routing.
Step 4 Switch(config)# interface [FastEthernet |
GigabitEthernet | Loopback | Null |
Port-channel | TenGigabitEthernet | Tunnel |
Vlan] number
Selects an interface that is connected to hosts on which PIM
can be enabled.