Specifications

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.3.0XO(15.1(1)XO)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
ipv6 mld snooping robustness-variable
ipv6 mld snooping robust ness-variable
To configure the number of IP version 6 (IPv6) Multicast Listener Discovery (MLD) queries that the
switch sends before deleting a listener that does not res pond, or to enter a VLAN ID to config ure the
number of queries per VLAN, use the ipv6 mld snooping robustness-variabl e command. To reset the
variable to the default settings, use the no form of this command.
ipv6 mld snooping [vlan vlan-id] robustness-variab le integer_value
no ipv6 mld snooping [vlan vlan -id ] robustness-variable
Syntax Description
Command Default The default global robustness variable (number of queries before deleting a listener) is 2.
The default VLAN robustness varia ble (number of querie s before aging out a multicast address) is 0,
which means that the system uses the global robustness varia ble for aging out the liste ner.
Command Modes Global c onfiguratio n mode
Usage Guidelines R obustne ss is measure d by the numb er of MLDv 1 queries sent with no resp onse befor e a port is r emoved
from a multicast group. A port is deleted when there are no MLDv1 reports received for the configured
number of MLDv1 queries. The global value determines the number of queries that the switch waits
before deleting a listener that does not respond, and it applies to all VLANs that do not have a VLAN
value set.
The robustness value configure d for a VLAN overrides the global value. If the VLA N robustness value
is 0 (the default), the global value is used.
VLAN numbers 1002 through 1005 are rese rved for Token Ring and FDDI VLANs and cann ot be used
in MLD snoopi ng.
Examples This exampl e shows how to configure the glob al robustness variabl e so that the switch sends out thr ee
queries before it deletes a listener port that does not r espond:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# ipv6 mld snooping robustness-variable 3
Switch(config)# end
Switch#
This example shows how to configure t he robustness variable for VL AN 1. This value overrides the
global configuration for the VLAN:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# ipv6 mld snooping vlan 1 robustness-variable 1
vlan vlan-id (Optional) Configures the robustness variable on the specified VLAN. The
VLAN ID range is 1 to 1001 and 1006 to 4094.
integer_value The robustness value ranges from 1 to 3.