Additional Igmp Features; Fastleave; Igmp Filtering - Lenovo Flex System Fabric CN4093 Application Manual

Additional IGMP Features

FastLeave

IGMP Filtering

Configuring the Range
Configuring the Action
© Copyright Lenovo 2015
The following topics are discussed in this section:
 "FastLeave" on page 399
 "IGMP Filtering" on page 399
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.
With IGMP Filtering, you can allow or deny a port to learn certain IGMP/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.
Each IGMP Filter allows you to set a start and end point that defines the range of
IPv4 addresses upon which the filter takes action. Each IPv4 address in the range
must be between 224.0.0.0 and 239.255.255.255.
Each IGMP filter can allow or deny IPv4 multicasts to the range of IPv4 addresses
configured. If you configure the filter to deny IPv4 multicasts, then IGMP
Membership Reports from multicast groups within the range are dropped. You can
configure a secondary filter to allow IPv4 multicasts to a small range of addresses
within a larger range that a primary filter is configured to deny. The two filters
work together to allow IPv4 multicasts to a small subset of addresses within the
larger range of addresses.
Chapter 28: Internet Group Management Protocol
399