Protocol Ethernet AddressPIM-SM 01:00:5e:00:00:0d• The Dell Networking OS implementation of MTRACE is in accordance with IETF draft draft-fenner-traceroute-ipm.• Multicast is not supported on secondary IP addresses.• Egress L3 ACL is not applied to multicast data traffic if you enable multicast routing.First Packet Forwarding for Lossless MulticastAll initial multicast packets are forwarded to receivers to achieve lossless multicast.In previous versions, when the Dell Networking system is an RP, all initial packets are dropped until PIMcreates an (S,G) entry. When the system is an RP and a Source DR, these initial packet drops represent aloss of native data, and when the system is an RP only, the initial packets drops represent a loss of registerpackets.Both scenarios might be unacceptable depending on the multicast application. When the DellNetworking system is the RP, and has receivers for a group G, it forwards all initial multicast packets forthe group based on the (*,G) entry rather than discarding them until the (S,G) entry is created, making DellNetworking systems suitable for applications sensitive to multicast packet loss.NOTE: When a source begins sending traffic, the Source DR forwards the initial packets to the RP asencapsulated registered packets. These packets are forwarded via the soft path at a maximum rateof 70 packets/second. Incoming packets beyond this rate are dropped.Multicast PoliciesDell Networking OS offers parallel multicast features for IPv4.• IPv4 Multicast PoliciesIPv4 Multicast PoliciesThe following sections describe IPv4 multicast policies.• Limiting the Number of Multicast Routes• Preventing a Host from Joining a Group• Preventing a PIM Router from Forming an Adjacency• Preventing a Source from Registering with the RP• Preventing a PIM Router from Processing a JoinLimiting the Number of Multicast RoutesWhen the total number of multicast routes on a system limit is reached, Dell Networking OS does notprocess any IGMP or multicast listener discovery protocol (MLD) joins to PIM — though it still processesleave messages — until the number of entries decreases below 95% of the limit.When the limit falls below 95% after hitting the maximum, the system begins relearning route entriesthrough IGMP, MLD, and MSDP.• If the limit is increased after it is reached, join subsequent join requests are accepted. In this case,increase the limit by at least 10% for IGMP and MLD to resume.530 Multicast Features
