1258 BigIron RX Series Configuration Guide53-1001810-01Multicast Listener Discovery and source specific multicast protocols(MLDv2)49Multicast Listener Discovery and source specific multicastprotocols(MLDv2)The Multicast Listener Discovery Version 2 (MLDv2) protocol is available on the BigIron RX that isrunning IPv6. IPv6 routers use the MLDv2 protocol to discover multicast listeners, or nodes thatwish to receive multicast packets on directly attached links. MLDv2 supports source filtering, theability of a node to send reports on traffic that is from a specific address source or from allmulticast addresses except the specified address sources. The information is then provided to thesource specific multicast (SSM) routing protocols such as PIM-SSM.The IPv6 switch stores a list of multicast addresses for each attached link. For each multicastaddress, the IPv6 switch stores a filter mode and a source list. The filter mode is set to INCLUDE ifall nodes in the source list for a multicast address are in the INCLUDE state. If the filter mode isINCLUDE, then only traffic from the addresses in the source list is allowed. The filter mode is set toEXCLUDE if at least one of the nodes in the source list is in an EXCLUDE state. If the filter mode isEXCLUDE, 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 querierrouter 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 belistened to on an interface.• Address specific query – The querier sends this query to determine if a specific multicastaddress has any listeners.• Address specific and source specific query – The querier sends this query to determine ifspecified sources of a specific multicast address have any listeners.In response o these queries, multicast listeners send the following reports:• Current state – This report specifies the source list for a multicast address and whether thefilter 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 thesource 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.NOTEPIM IPv4/IPv6 can only be configured on one physical port. The loopback interface does not countas one physical interface. The chassis will give you an error if you attempt to configure PIM on morethan on physical interface.NOTEIPv6 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 chassis.MLD version distinctionsMLDv1 mode interfaces exchange the following types of messages between routers and hosts:• Multicast listener queries
