NETGEAR GS700TS Series, User Manual

Page: 147 / 189

GS700TS Series Smart Switch Software User Manual
5-118 Configuring The Device Using Your Browser
v1.0, November 2006
• Registered Multicast traffic – If traffic addressed to a registered multicast group is seen it is
handled by an entry in the Multicast Filtering Database and forwarded only to the registered
ports.
• Unregistered Multicast traffic – If traffic addressed to an unregistered multicast group is
seen it is handled by a special entry in the Multicast Filtering Database. The default setting of
this is to flood all such traffic (traffic in unregistered multicast groups).
Layer 2 switching forwards multicast packets to all relevant VLAN ports by default, treating the
packet as a multicast transmission. Multicast traffic forwarding is functional. However, irrelevant
ports also receive the multicast, causing increased network traffic. Multicast forwarding filters
enable forwarding of Layer 2 packets to port subsets, defined in the multicast filter database.
The device supports forwarding L2 Multicast Packets. Multicast forwarding is enabled by default,
and not configurable by user.
This section contains the following topics:
• Configuring IGMP Snooping
• Defining Multicast Groups
• Configuring Multicast Forward All
Configuring IGMP Snooping
When IGMP snooping is enabled, 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, and what routing protocols are forwarding
packets and multicast traffic. Ports requesting to join a specific multicast group issues an IGMP
report specifying that multicast group.