Lenovo Flex System Fabric CN4093, Application Manual

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© Copyright Lenovo 2017 Chapter 27: Internet Group Management Protocol
443
Additional IGMP Features
The following topics are discussed in this section:
 “FastLeave” on page 443
 “IGMP Filtering” on page 443
FastLeave
In normal IGMP operation, when the switch receives an IGMPv2 leave message, it
sends a Group ‐ Specific Query to determine if any other devices in the same group
(and on the same port) are still interested in the specified multicast group traffic.
The switch removes the affiliated port from that particular group, if it does not
receive an IGMP Membership Report within the query ‐ response ‐ interval.
With FastLeave enabled on the VLAN, a port can be removed immediately from
the port list of the group entry when the IGMP Leave message is received, unless a
multicast router was learned on the port.
Enable FastLeave only on VLANs that have only one host connected to each
physical port.
IGMP Filtering
With IGMP Filtering, you can allow or deny a port to learn certain IGMP or IPMC
groups. This allows you to restrict users from receiving certain multicast traffic.
If access to a multicast group is denied, IGMP Membership Reports from the port
are dropped, and the port is not allowed to receive IPv4 multicast traffic from that
group. If access to the multicast group is allowed, Membership Reports from the
port are forwarded for normal processing.
To configure IGMP Filtering, you must globally enable IGMP filtering, define an
IGMP filter, assign the filter to a port, and enable IGMP Filtering on the port. To
define an IGMP filter, you must configure a range of IPv4 multicast groups, choose
whether the filter will allow or deny multicast traffic for groups within the range,
and enable the filter.