Black Box LGB6026A, Management Manual

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C
HAPTER
41 | Multicast Filtering Commands
IGMP Snooping
ip igmp snooping
router-port-expire-
time
This command configures the querier timeout. Use the no form to restore
the default.
S
YNTAX
ip igmp snooping router-port-expire-time seconds
no ip igmp snooping router-port-expire-time
seconds - The time the switch waits after the previous querier stops
before it considers it to have expired. (Range: 1-65535;
Recommended Range: 300-500)
D
EFAULT
S
ETTING
300 seconds
C
OMMAND
M
ODE
Global Configuration
E
XAMPLE
The following shows how to configure the timeout to 400 seconds:
Console(config)#ip igmp snooping router-port-expire-time 400
Console(config)#
ip igmp snooping
tcn-flood
This command enables flooding of multicast traffic if a spanning tree
topology change notification (TCN) occurs. Use the
no form to disable
flooding.
S
YNTAX
[ no ] ip igmp snooping tcn-flood
D
EFAULT
S
ETTING
Disabled
C
OMMAND
M
ODE
Global Configuration
C
OMMAND
U
SAGE
◆
When a spanning tree topology change occurs, the multicast
membership information learned by the switch may be out of date. For
example, a host linked to one port before the topology change (TC)
may be moved to another port after the change. To ensure that
multicast data is delivered to all receivers, by default, a switch in a
VLAN (with IGMP snooping enabled) that receives a Bridge Protocol
Data Unit (BPDU) with the TC bit set (by the root bridge) will enter into
“multicast flooding mode” for a period of time until the topology has
stabilized and the new locations of all multicast receivers are learned.