Users Guide

Deployment considerations
Dell EMC recommends the following:
• In a VLT-enabled PIM router, multicast routing is not supported when there are multiple PIM spanned paths to reach the source or RP.
Congure only one PIM spanned path to reach any PIM router in the aggregation or spine.
• If a source is connected to a nonspanned interface of the VLT peer nodes and the RP is reachable on a spanned interface from both
the VLT nodes, the receiver might receive duplicate trac. To avoid duplicate trac, congure the source to be reachable on a spanned
interface.
• For better convergence, the upstream incoming interface (IIF) and the downstream outgoing interface (OIF) must be a spanned VLAN.
• In VLT deployments, Dell EMC recommends not to change the PIM designated router by conguring a non-default value using the ip
pim dr-priority command.
• In large-scale multicast deployments, you might see frequent bursts of multicast control trac. For such deployments, Dell EMC
recommends that you increase the burst size for queue 2 on all PIM routers using control-plane policing. For more information on how
to congure a QoS policy to rate limit control-plane trac, see Congure control-plane policing.
NOTE: OS10 does not support Anycast RP.
Example: Spanned L3 VLAN IIF
This section describes how to congure VLT multicast routing in a four-node setup—core, AG1, AG2, and ToR—using the topology shown
in the following gure:
• Core, AG1, and AG2 are multicast routers in a VLT domain.
• ToR is an IGMP-enabled L2 switch.
• OSPF is the unicast routing protocol.
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Multicast