Ip Multicast Routing Configuration Guide, Cisco Ios Xe Release 3Se (Catalyst 3650 Switches - Cisco Catalyst 3650 Configuration Manual

Enabling ECMP Multicast Load Splitting
Enable ECMP multicast load splitting on the device that is to be the receiver for traffic from more than
Note
one incoming interfaces, which is opposite to unicast routing. From the perspective of unicast, multicast
is active on the sending device connecting to more than one outgoing interfaces.
Before You Begin
• You must have an adequate number of sources (at least more than two sources) to enable ECMP multicast
• You must have multiple paths available to the RP to configure ECMP multicast load splitting.
• When using PIM-SM with shortest path tree (SPT) forwarding, the T-bit mus be set for the forwarding
• Before configuring ECMP multicast load splitting, it is best practice to use the show ip rpf command
• BGP does not install multiple equal-cost paths by default. Use the maximum-paths command to configure
SUMMARY STEPS
1. enable
2. configure terminal
3. ip multicast multipath
4. Repeat step 3 on all the devices in a redundant topology.
5. exit
6. show ip rpf source-address [group-address]
7. show ip route ip-address
DETAILED STEPS
Command or Action
Step 1 enable
Example:
Device> enable

IP Multicast Routing Configuration Guide, Cisco IOS XE Release 3SE (Catalyst 3650 Switches)

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load splitting based on source address.
Note Use the show ip route command with either the IP address of the source for the
ip-addressargument or the IP address of the RP to validate that there are multiple paths
available to the source or RP, respectively. If you do not see multiple paths in the output
of the command, you will not be able to configure ECMP multicast load splitting.
of all (S, G) states.
to validate whether sources can take advantage of IP multicast multipath capabilities.
multipath (for example in BGP). For more information, see the
Splitting, on page 323 section.
Purpose
Enables privileged EXEC mode.
IP Multicast Optimization: IP Multicast Load Splitting across Equal-Cost Paths
• Enter your password if prompted.
Use of BGP with ECMP Multicast Load
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