Configuration Guide    MLD Snooping Configuration 
Figure 1 Two types of MLD Snooping ports 
Multicast Router Port: a multicast device of the switch to connect layer 3, e.g., Eth 0 / 
1 port; 
Member Port: the short form of the IPv6 multicast group member port, also called 
Listener Port. For example, the Access Switch Eth0/2、Eth0/3 and Eth0/4 port. 
MLD Profiles 
MLD Profiles are actually some group filters, which can define a series of multicast 
address  ranges,  and  permit  or  deny  the  access  of  those  multicast  addresses, 
providing usage for different functions of the following "multicast address ranges for 
SVGL mode application", "multicast data area to be filtered by router port", "MLD 
Filtering range", etc. 
Working Modes 
DISABLE  mode:  Under this  mode,  MLD  Snooping is  out of function,  i.e.,  layer  2 
multicast equipment does not "snoop" the MLD message between hosts and router, 
and multicast frames are broadcast in VLAN. 
IVGL (Independent VLAN Group Learn) working mode: Under this mode, multicast 
stream  among  all  VLANs  is  inter-independent.  A  host  can  only  request  multicast 
stream from the router port in the same VLAN where the host is located; switch can 
only transmit the multicast data flow being received from any VLAN to listener ports 
in the same VLAN. 
Working Principle 
The  switch  that  runs  MLD  Snooping  processes  different  MLD  messages  in  the 
following ways: 
1. MLD QUERY 
Layer  3  multicast  equipments  regularly send  group-general  query  message  to  all 
hosts and routers (address: FF 02::1) within local network segment to find out which 
listeners  of  IPv  6  multicast  group  exist  in  this  local  network  segment.  A  switch 
transmits MLD group-general query message being received to all other ports except 
receive port within VLAN and process the receive port in the following ways: 
  If the port is already included in the list of router ports, its aging timer should 
be reset. 
  If the port is not included in the list of router ports, it should be added to the 
list of router ports and its aging timer should be enabled. 
  Whenever receiving MLD group-general query message, layer 2 multicast 
equipment  will  update  respective  aging  timers  of  all  listener  ports  and