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Multicast Features
Multicast features are supported on the MXL switch platform.
The Dell Networking operating system (OS) supports the following multicast protocols:
•PIM Sparse-Mode (PIM-SM)
•PIM Source-Specific Mode (PIM-SSM)
•Internet Group Management Protocol (IGMP)
•Multicast Source Discovery Protocol (MSDP)

Enabling IP Multicast

Prior to enabling any multicast protocols, you must enable multicast routing.
• Enable multicast routing.
CONFIGURATION mode
ip multicast-routing
Implementation Information
Because protocol control traffic in the Networking OS is redirected using the MAC address, and multicast
control traffic and multicast data traffic might map to the same MAC address, the Dell Networking OS
might forward data traffic with certain MAC addresses to the CPU in addition to control traffic.
As the upper 5 bits of an IP Multicast address are dropped in the translation, 32 different multicast group
IDs all map to the same Ethernet address. For example, 224.0.0.5 is a known IP address for open shortest
path first (OSPF) that maps to the multicast MAC address 01:00:5e:00:00:05. However, 225.0.0.5,
226.0.0.5, and so on, map to the same multicast MAC address. The Layer 2 forwarding information base
(FIB) alone cannot differentiate multicast control traffic multicast data traffic with the same address, so if
you use IP address 225.0.0.5 for data traffic, both the multicast data and OSPF control traffic match the
same entry and are forwarded to the CPU. Therefore, do not use well-known protocol multicast
addresses for data transmission, such as the following.
Protocol Ethernet Address
OSPF 01:00:5e:00:00:05
01:00:5e:00:00:06
Multicast Features 603