Dell POWEREDGE M1000E User Manual
Page 1091
44-13
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
OL-13270-03
Chapter 44 Configuring IP Multicast Routing
Configuring IP Multicast Routing
Note
If you enable PIM on multiple interfaces, when most of these interfaces are not on the outgoing interface
list, and IGMP snooping is disabled, the outgoing interface might not be able to sustain line rate for
multicast traffic because of the extra replication.
In populating 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 devices 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
encapsulated and sent toward the RP. When no RP is known, the packet is flooded in a dense-mode
fashion. If the multicast traffic from a specific source is sufficient, the receiver’s first-hop router might
send join messages toward the source to build a source-based distribution tree.
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
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
ip multicast-routing distributed
Enable IP multicast distributed switching.
Step 3
interface interface-id
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
.
Step 4
ip pim version [1 | 2]
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.
“PIMv1 and PIMv2 Interoperability”
.