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This chapter contains the following sections:
To enable IPv6 Multicast Listener Discovery (MLD) snooping, use the ipv6 mld snooping command in Global Configuration mode. To return to the default, use the no form of this command.
ipv6 mld snooping
no ipv6 mld snooping
IPv6 MLD snooping is disabled.
Global Configuration mode
The following example enables IPv6 MLD snooping.
switchxxxxxx(config)# ipv6 mld snooping
To enable MLD snooping on a specific VLAN, use the ipv6 mld snooping vlan command in Global Configuration mode. To return to the default, use the no form of this command.
ipv6 mld snooping vlan vlan-id
no ipv6 mld snooping vlan vlan-id
vlan-id—Specifies the VLAN.
Disabled
Global Configuration mode
MLD snooping can only be enabled on static VLANs.
MLDv1 and MLDv2 are supported.
switchxxxxxx(config)# ipv6 mld snooping vlan 2
To enable globally the MLD Snooping querier, use the ipv6 mld snooping querier command in Global Configuration mode. To disable the MLD Snooping querier globally, use the no form of this command.
ipv6 mld snooping querier
no ipv6 mld snooping querier
Enabled
Global Configuration mode
To run the MLD Snooping querier on a VLAN, you have enable it globally and on the VLAN.
The following example disables the MLD Snooping querier globally:
switchxxxxxx(config)# no ipv6 mld snooping querier
To enable the Internet MLD Snooping querier on a specific VLAN, use the ipv6 mld snooping vlan querier command in Global Configuration mode. To return to the default, use the no form of this command.
ipv6 mld snooping vlan vlan-id querier
no ipv6 mld snooping vlan vlan-id querier
vlan-id—Specifies the VLAN.
Disabled
Global Configuration mode
The MLD Snooping querier can be enabled on a VLAN only if MLD Snooping is enabled for that VLAN.
The following example enables the MLD Snooping querier on VLAN 1:
switchxxxxxx(config)# ipv6 mld snooping vlan 1 querier
To enable MLD Querier election mechanism of an MLD Snooping querier on a specific VLAN, use the ipv6 mld snooping vlan querier election command in Global Configuration mode. To disable Querier election mechanism, use the no form of this command.
ipv6 mld snooping vlan vlan-id querier election
no ipv6 mld snooping vlan vlan-id querier election
vlan-id—Specifies the VLAN.
Enabled
Global Configuration mode
Use the no form of the ipv6 mld snooping vlan querier election command to disable MLD Querier election mechanism on a VLAN.
If the MLD Querier election mechanism is enabled, the MLD Snooping querier supports the standard MLD Querier election mechanism specified in RFC2710 and RFC3810.
If MLD Querier election mechanism is disabled, MLD Snooping Querier delays sending General Query messages for 60 seconds from the time it was enabled. During this time, if the switch did not receive an IGMP query from another Querier - it starts sending General Query messages. Once the switch acts as a Querier, it will stop sending General Query messages if it detects another Querier on the VLAN. In this case, the switch will resume sending General Query messages if it does hear another Querier for Query Passive interval that equals to
<Robustness>*<Query Interval> + 0.5*<Query Response Interval).
It is recommended to disable MLD Querier election mechanism if there is an IPMv6 Multicast router on the VLAN.
The following example disables MLD Snooping Querier election on VLAN 1:
switchxxxxxx(config)# no ipv6 mld snooping vlan 1 querier election
To configure the IGMP version of an IGMP querier on a specific VLAN, use the ipv6 mld snooping vlan querier version command in Global Configuration mode. To return to the default, use the no form of this command.
ipv6 mld snooping vlan vlan-id querier version {1 | 2}
no ipv6 mld snooping vlan vlan-id querier version
vlan-id—Specifies the VLAN.
querier version {1 | 2}—Specifies the MLD version.
MLDv1.
Global Configuration mode
he following example sets the version of the MLD Snooping Querier VLAN 1 to 2:
switchxxxxxx(config)# ipv6 mld snooping vlan 1 querier version 2
To enable automatic learning of Multicast router ports, use the ipv6 mld snooping vlan mrouter command in Global Configuration mode. To remove the configuration, use the no form of this command.
ipv6 mld snooping vlan vlan-id mrouter learn pim-dvmrp
no ipv6 mld snooping vlan vlan-id mrouter learn pim-dvmrp
vlan-id—Specifies the VLAN.
pim-dvmrp—Learn Multicast router port by PIM, DVMRP and MLD messages.
Learning pim-dvmrp is enabled.
Global Configuration mode
You can execute the command before the VLAN is created.
switchxxxxxx(config)# ipv6 mld snooping vlan 1 mrouter learn pim-dvmrp
To define a port that is connected to a Multicast router port, use the ipv6 mld snooping mrouter interface command in Global Configuration mode. To return to the default, use the no form of this command.
ipv6 mld snooping vlan vlan-id mrouter interface interface-list
no ipv6 mld snooping vlan vlan-id mrouter interface interface-list
vlan-id—Specifies the VLAN.
interface-list—Specifies a list of interfaces. The interfaces can be from one of the following types: port or port-channel.
No ports defined
Global Configuration mode
A port that is defined as a Multicast router port receives all MLD packets (reports and queries) as well as all Multicast data.
You can execute the command before the VLAN is created and for a range of ports as shown in the example.
switchxxxxxx(config)# interface gi1/0/1
switchxxxxxx(config-if)# ipv6 mld snooping vlan 1 mrouter interface gi1/0/1-4
To forbid a port from being defined as a Multicast router port by static configuration or by automatic learning, use the ipv6 mld snooping vlan forbidden mrouter command in Global Configuration mode. To return to the default, use the no form of this command.
ipv6 mld snooping vlan vlan-id forbidden mrouter interface interface-list
no ipv6 mld snooping vlan vlan-id forbidden mrouter interface interface-list
vlan-id—Specifies the VLAN.
interface-list—Specifies list of interfaces. The interfaces can be of one of the following types: Ethernet port or Port-channel.
No forbidden ports by default
Global Configuration mode
A port that is forbidden to be defined as a Multicast router port (mrouter port) cannot be learned dynamically or assigned statically.
You can execute the command before the VLAN is created.
switchxxxxxx(config)# ipv6 mld snooping vlan 1 forbidden mrouter interface gi1/0/1
To register a IPv6-layer Multicast address to the bridge table, and to add statically ports to the group, use the ipv6 mld snooping vlan static command in Global Configuration mode. To return to the default, use the no form of this command.
ipv6 mld snooping vlan vlan-id static ipv6-address [interface interface-list]
no ipv6 mld snooping vlan vlan-id static ipv6-address [interface interface-list]
vlan-id—Specifies the VLAN.
ipv6-address—Specifies the IP multicast address
interface interface-list—(Optional) Specifies list of interfaces. The interfaces can be from one of the following types: Ethernet port or Port-channel.
No Multicast addresses are defined.
Global Configuration mode
Static multicast addresses can only be defined on static VLANs.
You can execute the command before the VLAN is created.
You can register an entry without specifying an interface.
Using the no command without a port-list removes the entry.
switchxxxxxx(config)# ipv6 mld snooping vlan 1 static FF12::3 gi1/0/1
To enable MLD Snooping Immediate-Leave processing on a VLAN, use the ipv6 mld snooping vlan immediate-leave command in Global Configuration mode. To return to the default, use the no form of this command.
ipv6 mld snooping vlan vlan-id immediate-leave
no ipv6 mld snooping vlan vlan-id immediate-leave
vlan-id—Specifies the VLAN ID value. (Range: 1–4094)
Disabled
Global Configuration mode
When an MLD Leave Group message is received from a host, the system removes the host port from the table entry. After it relays the MLD queries from the Multicast router, it deletes entries periodically if it does not receive any MLD membership reports from the Multicast clients.
MLD snooping Immediate-Leave processing allows the switch to remove an interface that sends a leave message from the forwarding table without first sending out MAC-based general queries to the interface.
You can execute the command before the VLAN is created.
switchxxxxxx(config)# ipv6 mld snooping vlan 1 immediate-leave
To display the multicast groups learned by the MLD snooping, use the show ipv6 mld snooping groups EXEC mode command in User EXEC mode.
show ipv6 mld snooping groups [vlan vlan-id] [address ipv6-multicast-address] [source ipv6-address]
vlan vlan-id—(Optional) Specifies the VLAN ID.
address ipv6-multicast-address—(Optional) Specifies the IPv6 multicast address.
source ipv6-address—(Optional) Specifies the IPv6 source address.
User EXEC mode
Display information for all VLANs and addresses defined on them.
The Include list contains the ports which are in a forwarding state for this group according to the snooping database. In general, the Exclude list contains the ports which have issued an explicit Exclude for that specific source in a multicast group.
The Reporters That Are Forbidden Statically list contains the list of ports which have asked to receive a multicast flow but were defined as forbidden for that multicast group in a multicast bridge.
Note: Under certain circumstances, the Exclude list may not contain accurate information; for example, in the case when two Exclude reports were received on the same port for the same group but for different sources, the port will not be in the Exclude list but rather in the Include list
The following example shows the output for show ipv6 mld snooping groups.
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To display the IPv6 MLD snooping configuration for a specific VLAN, use the show ipv6 mld snooping interface EXEC mode command in User EXEC mode.
show ipv6 mld snooping interface vlan-id
vlan-id—Specifies the VLAN ID.
Display information for all VLANs.
User EXEC mode
The following example displays the MLD snooping configuration for VLAN 1000.
switchxxxxxx# show ipv6 mld snooping interface 1000
MLD Snooping is globally enabled
MLD Snooping Querier is globally enabled
VLAN 1000
MLD Snooping is enabled
MLD snooping last immediate leave: enable
Automatic learning of multicast router ports is enabled
MLD Snooping Querier is enabled
MLD Snooping Querier operation state: is running
MLD Snooping Querier version: 2
MLD Snooping Querier election is enabled
MLD snooping robustness: admin 2 oper 2
MLD snooping query interval: admin 125 sec oper 125 sec
MLD snooping query maximum response: admin 10 sec oper 10 sec
MLD snooping last member query counter: admin 2 oper 2
MLD snooping last member query interval: admin 1000 msec oper 500 msec
Groups that are in MLD version 1 compatibility mode:
FF12::3, FF12::8
To display information on dynamically learned Multicast router interfaces for all VLANs or for a specific VLAN, use the show ipv6 mld snooping mrouter EXEC mode command in User EXEC mode.
show ipv6 mld snooping mrouter [interface vlan-id]
interface vlan-id—(Optional) Specifies the VLAN ID.
Display information for all VLANs.
User EXEC mode
The following example displays information on dynamically learned Multicast router interfaces for VLAN 1000:
switchxxxxxx# show ipv6 mld snooping mrouter interface 1000
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VLAN ---- 1000 |
Dynamic --------- gi1/0/1 |
Static --------- gi1/0/2 |
Forbidden ---------- gi1/0/3-4 |
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