Enabling mldv2 – Brocade Multi-Service IronWare Multicast Configuration Guide (Supporting R05.6.00) User Manual

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Multi-Service IronWare Multicast Configuration Guide

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Multicast Listener Discovery and source-specific multicast protocols

Multicast Listener Discovery Version 2 (MLDv2) protocol is supported. 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 router stores a list of multicast addresses for each attached link. For each multicast
address, the IPv6 router 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.

Enabling MLDv2

MLDv1 is enabled once PIM Sparse Mode (PIM-SM) is enabled on an interface. You then enable
version 2 of MLD, the version that supports source filtering.

MLDv2 interoperates with MLDv1. MLDv1 messages are understood by MLDv2. When an IPv6
router detects that the node is operating in MLDv1 mode, the router switches to MLDv1 for that
node even though queries are sent in MLDv2.

To enable IPv6 PIM-SM, enter the following command at the interface level.

Brocade(config)# ipv6 router pim

Brocade(config-if-e10000-1/1)# ipv6 pim-sparse

Syntax: [no] ipv6 pim-sparse

Configuring MLD parameters for default and non-default VRFs

MLD allows you to configure the following parameters on default and non-default VRFs: