Huawei Quidway S3100 Series Operation Manual page 330

Operation Manual – IGMP Snooping
Quidway S3100 Series Ethernet Switches
II. Layer 2 multicast with IGMP Snooping
The switch runs IGMP Snooping to listen to IGMP messages and map the hosts and
the ports that connect the hosts to the corresponding multicast group addresses.
IGMP-enabled router
IGMP Snooping-enabled
Ethernet switch
Figure 1-2 IGMP Snooping implementation
To implement Layer 2 multicast, the switch processes four different types of IGMP
messages it received, as shown in Table 1-3.
Table 1-3 IGMP Snooping messages
Mes
sage
Sen Recei Purpo
der ver se
Query
if the
multica
st
groups
contain
any
memb
er
Query
if
specifi
c
multica
st
group
contain
s any
memb
er
Huawei Technologies Proprietary
Chapter 1 IGMP Snooping Configuration
Internet
Internet
IGMP message
IGMP message
Switch action
Check if the message
comes from the original
router port
a
Send a group-specific query message to the IP
multicast group being queried.
1-3
If yes, reset the aging
timer of the router port.
If not, notify the
multicast router that a
member is in a
multicast group and
start the aging timer for
the router port.