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Configuration prerequisites
Before you configure parameters for IGMP messages in a VLAN, complete the following tasks:
•
Enable IGMP snooping for the VLAN.
•
Determine the source IP address of IGMP general queries.
•
Determine the source IP address of IGMP group-specific queries.
•
Determine the source IP address of IGMP reports.
•
Determine the source IP address of IGMP leave messages.
•
Determine the 802.1p priority of IGMP messages.
Configuring source IP addresses for IGMP messages
A Layer 2 device does not enlist the port that receives an IGMP query whose source IP address is
0.0.0.0 on a port as a dynamic router port. This might prevent multicast forwarding entries from being
correctly created at the data link layer and eventually cause multicast traffic forwarding failures.
To avoid this problem, when a Layer 2 device acts as the IGMP snooping querier, you can configure
a non-all-zero IP address as the source IP address of IGMP queries. You can also change the source
IP address of IGMP messages sent by a simulated member host or an IGMP snooping proxy.
Changing the source address of IGMP queries might affect the IGMP querier election within the
subnet.
To configure source IP addresses for IGMP messages in a VLAN:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter VLAN view.
vlan vlan-id
N/A
3.
Configure the source IP
address for IGMP
general queries.
igmp-snooping
general-query source-ip
ip-address
The default setting is the IP address of the
current VLAN interface. If the current
VLAN interface does not have an IP
address, the source IP address is 0.0.0.0.
4.
Configure the source IP
address for IGMP
group-specific queries.
igmp-snooping
special-query source-ip
ip-address
By default, the source IP address of IGMP
group-specific queries is one of the
following:
•
The source address of IGMP
group-specific queries if the IGMP
snooping querier has received IGMP
general queries.
•
The IP address of the current VLAN
interface if the IGMP snooping
querier does not receive an IGMP
general query.
•
0.0.0.0 if the IGMP snooping querier
does not receive an IGMP general
query and the current VLAN
interface does not have an IP
address.
5.
Configure the source IP
address for IGMP
reports.
igmp-snooping report
source-ip
ip-address
The default setting is the IP address of the
current VLAN interface. If the current
VLAN interface does not have an IP
address, the source IP address is 0.0.0.0.
6.
Configure the source IP
address for IGMP leave
igmp-snooping leave
source-ip
ip-address
The default setting is the IP address of the
current VLAN interface. If the current