H3C S7500 Series Operation Manual page 440

Operation Manual – Multicast
H3C S7500 Series Ethernet Switches
Timer
Query response
timer
II. Layer 2 multicast with IGMP Snooping
The switch runs IGMP Snooping to listen to IGMP messages and establish mapping
among the host, the port corresponding to the host, and the corresponding multicast
MAC address.
IGMP Snooping-enabled Switch
Figure 3-2 IGMP Snooping implementation
To implement Layer 2 multicast, the switch processes four different types of IGMP
messages it received, as shown in
Table 3-3 IGMP Snooping messages
Messag
e
IGMP
general
query
message
Setting
Query response
timeout time
IGMP-enabled Router
Sen Receiv
der er
Multi Multicas
cast t
route member
r and switch
multi and
cast host
switc
h
Chapter 3 IGMP Snooping Configuration
Packet normally
received before
timeout
IGMP report
message
Source
IGMG Message
IGMP Message
Table 3-3.
Purpos
Action of the multicast member switch
e
Query if
the
multica
Check if the
st
message comes
groups
from the original
contain
router port
any
membe
r
3-3
Timeout action
on the switch
Remove the port
from the member
port list of the
multicast group.
If yes, reset the
aging timer of the
router port
If not, notify all the
members of the
multicast router to
join a specific
multicast group and
start the aging
timer for the router
port