29Multicast FeaturesMulticast features are supported on Dell Networking OS.NOTE: Multicast is supported on secondary IP addresses on the platform.NOTE: Multicast routing for IPv6 is not supported.NOTE: Multicast routing is supported across default and non-default VRFs.The Dell Networking Operating System (OS) supports the following multicast protocols:• PIM Sparse-Mode (PIM-SM)• Internet Group Management Protocol (IGMP)• Multicast Source Discovery Protocol (MSDP)Enabling IP MulticastEnable IP multicast is supported on the Z9000S6000 platform.Prior to enabling any multicast protocols, you must enable multicast routing.• Enable multicast routing.CONFIGURATION modeip multicast-routingMulticast with ECMPDell Networking multicast uses equal-cost multi-path (ECMP) routing to load-balance multiple streamsacross equal cost links.When creating the shared-tree protocol independent multicast (PIM) uses routes from all configuredrouting protocols to select the best route to the rendezvous point (RP). If there are multiple, equal-costpaths, the PIM selects the route with the least number of currently running multicast streams. If multipleroutes have the same number of streams, PIM selects the first equal-cost route the route table manager(RTM) returns.In the following illustration, the receiver joins three groups. The last-hop DR initially has two equal-costroutes to the RP with no streams, so it non-deterministically selects Route 1 for the Group 1 IGMP Joinmessage. Route 1 then has one stream associated with it, so the last-hop DR sends the Group 2 Join byRoute 2. It then non-deterministically selects Route 2 for the Group 3 Join because both routes alreadyhave one multicast stream.528 Multicast Features
