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Step
Command
Remarks
2.
Enter interface view.
interface
interface-type
interface-number
N/A
3.
Configure a multicast group
policy.
igmp group-policy
ipv4-acl-number
[
version-number
]
By default, no IGMP multicast
group
policy exists on an
interface. Hosts attached to the
interface can join any multicast
groups.
Adjusting IGMP performance
Before adjusting IGMP performance, complete the following tasks:
•
Configure any unicast routing protocol so that all devices can interoperate at the network layer.
•
Configure basic IGMP features.
Configuring IGMP query and response parameters
The following are IGMP query and response parameters:
•
IGMP querier's robustness variable
—Number of times for retransmitting IGMP queries in
case of packet loss. A higher robustness variable makes the IGMP querier more robust, but
increases the timeout time for multicast groups.
•
IGMP startup query interval
—Interval at which an IGMP querier sends IGMP general queries
at startup.
•
IGMP startup query count
—Number of IGMP general queries that an IGMP querier sends at
startup.
•
IGMP general query interval
—Interval at which an IGMP querier sends IGMP general queries
to check for multicast group members on the network.
•
IGMP last member query interval
—In IGMPv2, it sets the interval at which a querier sends
group-specific queries after receiving a leave message. In IGMPv3, it sets the interval at which
a querier sends group-and-source-specific queries after receiving a report that changes
multicast source and group mappings.
•
IGMP last member query count
—In IGMPv2, it sets the number of group-specific queries that
a querier sends after receiving a leave message. In IGMPv3, it sets the number of
group-and-source-specific queries that a querier sends after receiving a report that changes
multicast source and group mappings.
•
IGMP maximum response time
—Maximum time before a receiver responds with a report to
an IGMP general query. This per-group timer is initialized to a random value in the range of 0 to
the maximum response time specified in the IGMP query. When the timer value for a group
decreases to 0, the receiver sends an IGMP report to the group.
•
IGMP other querier present timer
—Lifetime for an IGMP querier after a non-querier receives
an IGMP general query. If the non-querier does not receive a new query when this timer
expires, the non-querier considers that the querier has failed and starts a new querier election.
Configuration restrictions and guidelines
When you configure the IGMP query and response parameters, follow these restrictions and
guidelines:
•
You can configure the IGMP query and response parameters globally for all interfaces in IGMP
view or for an interface in interface view. For an interface, the interface-specific configuration
takes priority over the global configuration.