Service Manual

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Multicast Features
Multicast 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 Multicast
Enable IP multicast is supported on the S6000 platform.
Prior to enabling any multicast protocols, you must enable multicast routing.
• Enable multicast routing.
CONFIGURATION mode
ip multicast-routing
Implementation Information
Because protocol control trac in Dell Networking OS is redirected using the MAC address, and multicast control trac and
multicast data trac might map to the same MAC address, Dell Networking OS might forward data trac with certain MAC
addresses to the CPU in addition to control trac.
As the upper5 bits of an IP Multicast address are dropped in the translation, 32 dierent 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 rst (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 dierentiate multicast control trac multicast data trac with the same address, so
if you use IP address 225.0.0.5 for data trac, both the multicast data and OSPF control trac 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
RIP 01:00:5e:00:00:09
NTP 01:00:5e:00:01:01
VRRP 01:00:5e:00:00:12
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Multicast Features