3Com Switch 7750 Configuration Guide Guide

388 CHAPTER 40: IGMP SNOOPING CONFIGURATION
IGMP
host
report
message
Host
Multicast
router
and
multicast
switch
Apply for
joining a
multicast
group, or
respond
to an
IGMP
query
message
Check
if the
IP
multic
ast
group
has a
corres
pondi
ng
MAC
multic
ast
group
If yes,
check
if the
port
exists
in the
MAC
multic
ast
group
If yes, add the IP multicast
group address to the MAC
multicast group table.
If not, add the port to
the MAC multicast
group, reset the aging
timer of the port and
check if the
corresponding IP
multicast group exists.
If yes,
add
the
port to
the IP
multic
ast
group.
If not,
create
an IP
multic
ast
group
and
add
the
port to
it.
If not:
■ Create a MAC multicast group and
notify the multicast router that a
member is ready to join the multicast
group.
■ Add the port to the MAC multicast
group and start the aging timer of
the port.
■ Add all router ports in the VLAN
owning this port to the MAC
multicast group.
■ Create an IP multicast group and add
the port to it.
Table 305 IGMP Snooping messages
Message Sender Receiver Purpose Action of the multicast member switch