Ip Igmp Snooping Source-Only-Learning - Cisco Catalyst 2950 Command Reference Manual

Chapter 2 Catalyst 2950 and 2955 Cisco IOS Commands

ip igmp snooping source-only-learning

Use the ip igmp snooping source-only-learning global configuration command to enable IP
multicast-source-only learning on the switch and optionally set the aging time of the forwarding-table
entries that are learned. Use the no form of this command to disable IP multicast-source-only learning
or to disable aging.
Syntax Description age-timer
time
Defaults
IP multicast-source-only learning is enabled.
The aging feature is enabled. The default is 600 seconds (10 minutes).
Command Modes
Global configuration
Command History Release
12.1(11)EA1
Usage Guidelines
When IP multicast-source-only learning is enabled, the switch learns the IP multicast group from the IP
multicast data stream and only forwards traffic to the multicast router ports.
Note We strongly recommend that you do not disable IP multicast-source-only learning. IP
multicast-source-only learning should be disabled only if your network is not composed of IP
multicast-source-only networks and if disabling this learning method improves the network
performance.
In a source-only network, switch ports are connected to multicast source ports and multicast router ports.
The switch ports are not connected to hosts that send IGMP join or leave messages.
The switch learns about IP multicast groups from the IP multicast data stream by using the source-only
learning method. The switch forwards traffic only to the multicast router ports. You can disable
source-only learning by using the no ip igmp snooping source-only learning global configuration
command.
OL-10102-01
ip igmp snooping source-only-learning [age-timer value]
no ip igmp snooping source-only-learning [age-timer]
(Optional) Configure the aging time of the forwarding-table entries that the
switch learns by using the source-only learning method.
Aging time is seconds. The range is 0 to 2880 seconds. If you set time to 0, aging
of the forward-table entries is disabled.
Modification
This command was introduced.
Catalyst 2950 and Catalyst 2955 Switch Command Reference
ip igmp snooping source-only-learning
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