Cisco Catalyst 4500 Series Administration Guide

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Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)E
OL_28731-01
Chapter 37 Configuring IP Multicast
Configuring IP Multicast Routing
Note Source-specific multicast and IGMP v3 are supported.
For more information about source-specific multicast with IGMPv3 and IGMP, see the following URL:
http://www.cisco.com/en/US/docs/ios/ipmulti/configuration/guide/imc_cfg_ssm.html
Enabling IP Multicast Routing
Enabling IP multicast routing allows the Catalyst 4500 series switch to forward multicast packets. To
enable IP multicast routing on the router, enter this command:
Enabling PIM on an Interface
Enabling PIM on an interface also enables IGMP operation on that interface. An interface can be
configured to be in dense mode, sparse mode, or sparse-dense mode. The mode determines how the
Layer 3 switch or router populates its multicast routing table and how the Layer 3 switch or router
forwards multicast packets it receives from its directly connected LANs. You must enable PIM in one of
these modes for an interface to perform IP multicast routing.
When the switch populates the multicast routing table, dense-mode interfaces are always added to the
table. Sparse-mode interfaces are added to the table only when periodic join messages are received from
downstream routers, or when there is a directly connected member on the interface. When forwarding
from a LAN, sparse-mode operation occurs if there is an RP known for the group. If so, the packets are
Table 37-1 Default IP Multicast Configuration
Feature Default Value
Rate limiting of RPF Enabled globally
IP multicast routing Disabled globally
Note When IP multicast routing is disabled, IP multicast traffic data
packets are not forwarded by the Catalyst 4500 series switch.
However, IP multicast control traffic continues to be processed and
forwarded. IP multicast routes can remain in the routing table even
if IP multicast routing is disabled.
PIM Disabled on all interfaces
IGMP snooping Enabled on all VLAN interfaces
Note If you disable IGMP snooping on an interface, all output ports are
forwarded by the integrated switching engine. When IGMP
snooping is disabled on an input VLAN interface, multicast packets
related to that interface are sent to all forwarding switch ports in the
VLAN.
Command Purpose
Switch(config)# ip multicast-routing
Enables IP multicast routing.

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E