Dell PowerEdge VRTX - Manual (Page 346)

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FILE LOCATION: C:\Users\gina\Desktop\Checkout_new\Dell Plasma\User
Guide\Plasma_UGSwitching_Multicast.fm
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The device supports:
• Forwarding L2 Multicast Packets — Forwards Layer 2 Multicast
packets. Layer 2 Multicast filtering is enabled by default, and is not
user-configurable.
• Filtering L2 Multicast Packets — Forwards Layer 2 packets to
interfaces. If Multicast filtering is disabled, Multicast packets are
flooded to all relevant ports.
NOTE: The system supports Multicast filtering for 256 Multicast groups.
Layer 2 Switching
Layer 2 switching forwards Multicast packets to all relevant VLAN ports by
default, managing the packet as a single Multicast transmission. While
Multicast traffic forwarding is effective, it is not optimal, as irrelevant ports
also receive the Multicast packets. The excess packets cause increased
network traffic. Multicast forwarding filters enable forwarding of Layer 2
packets to a subset of ports instead of to all ports.
IGMP
Internet Group Multicast Protocol (IGMP) adds IGMP packets to Multicast
traffic. When IGMP Snooping is enabled globally, all IGMP packets are
forwarded to the CPU. The CPU analyzes the incoming packets and
determines:
• Which ports want to join which Multicast groups.
• Which ports have Multicast routers generating IGMP queries.
• What routing protocols are forwarding packets and Multicast traffic.
Ports requesting to join a specific Multicast group issue an IGMP report,
specifying that the Multicast group is accepting members. This results in the
creation of an entry in the Multicast filtering database.
Global Parameters
To enable Multicast filtering and IGMP Snooping:
1 Click Switching > Multicast Support > Global Parameters in the tree
view to display the Global Parameters page.