Cisco WS-C3750-48PS-S Software Configuration Manual page 813

Chapter 36 Configuring IP Multicast Routing
By default, multicast routing is disabled, and there is no default mode setting. This procedure is required.
Beginning in privileged EXEC mode, follow these steps to enable IP multicasting, to configure a PIM
version, and to configure a PIM mode. This procedure is required.
Command
Step 1 configure terminal
Step 2 ip multicast-routing distributed
Step 3
interface interface-id
Step 4
ip pim version [1 | 2]
Step 5 ip pim {dense-mode | sparse-mode |
sparse-dense-mode}
Step 6
end
Step 7 show running-config
Step 8 copy running-config startup-config
78-16180-02
Purpose
Enter global configuration mode.
Enable IP multicast distributed switching.
Specify the Layer 3 interface on which you want to enable multicast
routing, and enter interface configuration mode.
The specified interface must be one of the following:
A routed port: a physical port that has been configured as a Layer 3
•
port by entering the no switchport interface configuration
command.
An SVI: a VLAN interface created by using the interface vlan
•
vlan-id global configuration command.
These interfaces must have IP addresses assigned to them. For more
information, see the "Configuring Layer 3 Interfaces" section on
page 11-21.
Configure the PIM version on the interface.
By default, Version 2 is enabled and is the recommended setting.
An interface in PIMv2 mode automatically downgrades to PIMv1 mode
if that interface has a PIMv1 neighbor. The interface returns to Version 2
mode after all Version 1 neighbors are shut down or upgraded.
For more information, see the
section on page 36-9.
Enable a PIM mode on the interface.
By default, no mode is configured.
The keywords have these meanings:
dense-mode—Enables dense mode of operation.
•
sparse-mode—Enables sparse mode of operation. If you configure
•
sparse-mode, you must also configure an RP. For more information,
see the "Configuring a Rendezvous Point" section on page
sparse-dense-mode—Causes the interface to be treated in the mode
•
in which the group belongs. Sparse-dense-mode is the recommended
setting.
After you enable a PIM mode on the interface, the ip
Note
mroute-cache distributed interface configuration command is
automatically entered for the interface and appears in the running
configuration.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3750 Switch Software Configuration Guide
Configuring IP Multicast Routing
"PIMv1 and PIMv2 Interoperability"
36-12.
36-11