2-20
Displaying and Maintaining IGMP Snooping
To do...
Use the command...
Remarks
Display IGMP snooping multicast
group information (on a centralized
device)
display igmp-snooping group
[
vlan
vlan-id
] [
verbose
]
Available in
any view
Display the statistics information of
IGMP messages learned by IGMP
snooping
display igmp-snooping statistics
Available in
any view
Clear IGMP snooping multicast
group information
reset
igmp-snooping group
{
group-address
|
all
} [
vlan
vlan-id
]
Available in
user view
Clear the statistics information of all
kinds of IGMP messages learned
by IGMP snooping
reset igmp-snooping statistics
Available in
user view
z
The
reset igmp-snooping group
command works only on an IGMP snooping–enabled VLAN.
z
The
reset igmp-snooping group
command cannot clear the IGMP snooping multicast group
information for static joins.
IGMP Snooping Configuration Examples
Group Policy and Simulated Joining Configuration Example
Network requirements
z
As shown in
Figure 2-4
, Router A connects to the multicast source through GigabitEthernet 1/0/2
and to Switch A through GigabitEthernet 1/0/1.
z
IGMPv2 is required on Router A, IGMP snooping version 2 is required on Switch A, and Router A
will act as the IGMP querier on the subnet.
z
It is required that the receivers, Host A and Host B, attached to Switch A can receive multicast
traffic addressed to multicast group 224.1.1.1 only.
z
It is required that multicast data for group 224.1.1.1 can be forwarded through GigabitEthernet
1/0/3 and GigabitEthernet 1/0/4 of Switch A even if Host A and Host B accidentally, temporarily
stop receiving multicast data.
