Brocade BigIron RX Series Configuration Guide - Manual (Page 1437)

BigIron RX Series Configuration Guide 1359
53-1002484-04
Multicast Listener Discovery and source specific multicast protocols (MLDv2)
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Multicast Listener Discovery and source specific multicast
protocols (MLDv2)
The Multicast Listener Discovery Version 2 (MLDv2) protocol is available on the BigIron RX that is
running IPv6. IPv6 routers use the MLDv2 protocol to discover multicast listeners, or nodes that
wish to receive multicast packets on directly attached links. MLDv2 supports source filtering, the
ability of a node to send reports on traffic that is from a specific address source or from all
multicast addresses except the specified address sources. The information is then provided to the
source specific multicast (SSM) routing protocols such as PIM-SSM.
The IPv6 switch stores a list of multicast addresses for each attached link. For each multicast
address, the IPv6 switch stores a filter mode and a source list. The filter mode is set to INCLUDE if
all nodes in the source list for a multicast address are in the INCLUDE state. If the filter mode is
INCLUDE, then only traffic from the addresses in the source list is allowed. The filter mode is set to
EXCLUDE if at least one of the nodes in the source list is in an EXCLUDE state. If the filter mode is
EXCLUDE, traffic from nodes in the source list is denied and traffic from other sources is allowed.
The source list and filter mode are created when the IPv6 querier router sends a query. The querier
router is the one with the lowest source IPv6 address. It sends out any of the following queries:
• General query – The querier sends this query to learn all multicast addresses that need to be
listened to on an interface.
• Address specific query – The querier sends this query to determine if a specific multicast
address has any listeners.
• Address specific and source specific query – The querier sends this query to determine if
specified sources of a specific multicast address have any listeners.
In response to these queries, multicast listeners send the following reports:
• Current state – This report specifies the source list for a multicast address and whether the
filter mode for that source list is INCLUDE or EXCLUDE.
• Filter-mode change – This report specifies if there has been a change to the filter mode for the
source list and provides a new source list.
• Source list change – This report specifies the changes to the source list.
MLDv1 is compatible with IGMPv2 and MLDv2 is compatible with IGMPv3.
NOTE
PIM IPv4/IPv6 can only be configured on one physical port. The loopback interface does not count
as one physical interface. The device will give you an error if you attempt to configure PIM on more
than on physical interface.
NOTE
IPv6 will not be work unless all line cards are on the same version. If one LP is not the IPv6 version,
IPv6 will not work on the device.
MLD version distinctions
MLDv1 mode interfaces exchange the following types of messages between routers and hosts:
• Multicast listener queries