H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – Multicast
H3C S7500 Series Ethernet Switches Chapter 3
IGMP Snooping Configuration
3-3
Packet normally
Timeout action
Timer Setting
received before
on the switch
timeout
Query response
timer
Query response
timeout time
IGMP report
message
Remove the port
from the member
port list of the
multicast group.
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.
Source
IGMP-enabled Router
IGMP Snooping-enabled Switch
IGMG Message
IGMP Message
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.
Table 3-3 IGMP Snooping messages
Messag
e
Sen
der
Receiv
er
Purpos
e
Action of the multicast member switch
If yes, reset the
aging timer of the
router port
IGMP
general
query
message
Multi
cast
route
r and
multi
cast
switc
h
Multicas
t
member
switch
and
host
Query if
the
multica
st
groups
contain
any
membe
r
Check if the
message comes
from the original
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