Igmp Snooping Querier - Cisco 350XG series Administration Manual

Multicast
Multicast Forwarding
NOTE
Cisco 350XG & 550XG Series 10G Stackable Managed Switches
The following versions are supported:
• IGMP v1/v2/ v3
• MLD v1/v2
The device supports IGMP/MLD Snooping only on static VLANs. It does not
support IGMP/MLD Snooping on dynamic VLANs.
When IGMP/MLD Snooping is enabled globally or on a VLAN, all IGMP/MLD
packets are forwarded to the CPU. The CPU analyzes the incoming packets, and
determines the following:
• Which ports are asking to join which Multicast groups on what VLAN.
• Which ports are connected to Multicast routers (Mrouters) that are
generating IGMP/MLD queries.
• Which ports are receiving PIM, DVMRP, or IGMP/MLD query protocols.
These VLANs are displayed on the
page.
Ports, asking to join a specific Multicast group, issue an IGMP/MLD report that
specifies which group(s) the host wants to join. This results in the creation of a
forwarding entry in the Multicast Forwarding Data Base.

IGMP Snooping Querier

The IGMP/MLD Snooping Querier is used to support a Layer 2 Multicast domain of
snooping switches in the absence of a Multicast router. For example, where
Multicast content is provided by a local server, but the router (if one exists) on that
network does not support Multicast.
The device can be configured to be an IGMP Querier as a backup querier, or in
situation where a regular IGMP Querier does not exist. The device is not a full
capability IGMP Querier.
If the device is enabled as an IGMP Querier, it starts after 60 seconds have passed
with no IGMP traffic (queries) detected from a Multicast router. In the presence of
other IGMP Queriers, the device might (or might not) stop sending queries, based
on the results of the standard querier selection process.
IGMP/MLD Snooping IP Multicast Group
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