Filter
Top Products
DES-7200 Configuration Guide Chapter 4 MLD
Configuration
4-4
Fig 4 MLDv2 forwarding diagram
Compared with version 2, version 2 defines the following two types of messages:
Membership Listener Query
Membership Listener Report
Membership Query can be classified into:
General Query: Used to learn the information of all multicast listeners on the
attached link;
Group-Specific Query: Used to learn the information of group-specific listeners on
the attached link;
Group-and-Source-Specific Query: This type is newly added by MLDv2, and is
used to learn if any of listeners on the attached link needs to receive the
group-specific multicast streams sent by the specified source list.
Different from the Membership Report described in MLD Version1, the
Membership Report message sent by MLD Version2 may contain the information
of multiple groups. The destination address of Report message is FF02::16 in
MLDv2, and can carry one ore more group records, each of which contains the
group address and source address. The types of group records are shown below:
IS_IN: indicates that filtering mode between multicast group and multicast source
list is INCLUDE, i.e., only the multicast data sent from the specified multicast
source list to this multicast group will be received.
IS_EX: indicates that filtering mode between multicast group and multicast source
list is EXCLUDE, i.e., only the multicast data sent from multicast sources outside
the specified multicast source list to this multicast group will be received.
TO_IN: indicates that the filtering mode between multicast group and multicast
source list will change from EXCLUDE mode to INCLUDE mode.
TO_EX: indicates that the filtering mode between multicast group and multicast
source list will change from INCLUDE mode to EXCLUDE mode.
ALLOW: allows the receipt of multicast data from certain multicast sources. If the
current corresponding relationship is INCLUDE, these multicast sources will be
added into the existing multicast source list; if the current corresponding
relationship is EXCLUDE, these multicast sources will be deleted from the
existing multicast source list.
BLOCK: no longer expects to receive multicast data from certain multicast
sources. If the current corresponding relationship is INCLUDE, these multicast
sources will be deleted from the existing multicast source list; if the current
corresponding relationship is EXCLUDE, these multicast sources will be added
into the existing multicast source list.
In consideration of compatibility, MLD Version2 can also recognize the