Huawei Quidway S3900 Series Operation Manual page 372

Operation Manual – Multicast Protocol
Quidway S3900 Series Ethernet Switches-Release 1510
II. Layer 2 multicast with IGMP Snooping
The switch runs IGMP Snooping to listen to IGMP messages and map the host, the port
corresponding to the host, and the corresponding multicast MAC address.
IGMP-enabled router
IGMP Snooping-enabled
Ethernet switch
Figure 2-2 IGMP Snooping implementation
To implement Layer 2 multicast, the switch processes four different types of IGMP
messages it received, as shown in Table 2-3.
Table 2-3 IGMP Snooping messages
Message Sender
IGMP Multica
general st
query router
message and
multica
st
switch
IGMP Multica
group-sp st
ecific router
query and
message multica
st
switch
Internet
Receiver Purpose
Multicast Query if
member the
switch multicast
and host groups
contain
any
member
Multicast Query if a
member specific
switch IGMP
and host multicast
group
contains
any
member
Huawei Technologies Proprietary
Chapter 2 IGMP Snooping Configuration
Internet
IGMP message
IGMP message
Switch action
Check if the
message comes
from the original
router port
Send an IGMP group-specific query message to
the IP multicast group being queried.
2-3
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