Configuring MLD Attributes

You can configure MLD Attributes using the following set of tasks:

Note: You can configure MLD only on IPv6 interfaces. For information about configuring IPv6 interfaces, see Configuring IPv6 in the JunosE IP, IPv6, and IGP Configuration Guide.

Configuring MLD SSM Mapping

SSM mapping statically assigns sources to MLDv1 groups. You must use SSM mapping for MLDv1 hosts to interoperate with PIM SSM. SSM mapping allows the router to use a statically configured list to translate (*,G) memberships to (S,G) memberships.

The ipv6 mld ssm-map static command uses IPv6 access lists, which allow both source and destination/group addresses to be specified. You must set the source address to “any”.

To statically configure SSM mapping:

Enable SSM mapping on the router.
host1:boston(config)#ipv6 mld ssm-map enable
Use the no version to disable the SSM map.
Specify an access list and source address for use in SSM mapping.
host1:boston(config)#ipv6 mld ssm-map static boston-list 2001::1
Use the no version to remove the SSM map association.
Note: To operate correctly, the static source addresses must fall within the configured PIM SSM range.

Limiting the Number of Accepted MLD Groups

You can manage multicast traffic on the router by restricting the number of MLD groups.

To limit the number of accepted MLD groups:

Configure the maximum number of MLD groups that an interface can accept.
host1:boston(config-if)#ipv6 mld group limit 5
Use the no version to restore the default situation, in which there is no limit on the number of MLD groups that an interface can accept.

Configure the maximum number of MLD groups that a port can accept.

On ERX models:
host1(config)#multicast group port 3/0 limit 5
On E120 and E320 routers:
host1(config)#multicast group port 3/1/0 limit 5

Note: You can specify the identifier for the port in slot/port format (ERX routers) or in slot/adapter/port format (E120 and E320 routers) and the maximum number of MLD groups that interfaces can accept.

slot—Number of the chassis slot in the range 0–6 (ERX7xx models), 0–13 (ERX14xx models), 0–5 (E120 router), or 0–16 (E320 router)
adapter—Number of the bay in which the I/O adapter (IOA) resides. This identifier applies to the E120 and E320 routers only. In the software, adapter 0 identifies the right IOA bay (E120 router) and the upper IOA bay (E320 router); adapter 1 identifies the left IOA bay (E120 router) and the lower IOA bay (E320 router).
port—Port number on the I/O module or IOA

Use the no version to restore the default situation, in which there is no limit on the number of MLD groups that a port can accept.

Including and Excluding MLD Traffic

MLD allows you to include or exclude specific multicast traffic sources.

To include and exclude traffic:

Configure the interface to statically include the MLD (S,G) membership for a host that is not capable of dynamically signaling group membership.
host1:boston(config-if)#ipv6 mld static-include 2001::1 ff0e::1
Use the no version to remove the static designation.
Configure the interface to statically exclude the MLD (S,G) membership for a host that is not capable of dynamically signaling group membership.
host1:boston(config-if)#ipv6 mld static-exclude 2001::1 ff0e::1
Use the no version to remove the static designation.

Configuring MLD Explicit Host Tracking

Explicit host tracking enables the router to explicitly track each individual host that is joined to a group or channel on a particular multi-access network.

To enable explicit host tracking on the interface:

Configure the MLD version for the interface.
host1(config)#interface 3/0.101host1(config-if)#ipv6 mld version 2
Enable explicit host tracking on the interface without the capability of being automatically disabled even if MLD V1 hosts are detected on the MLD V2 interface. This tracking continues for a group even if the group downgrades to MLD V1 due to the presence of an MLD V1 host.
host1(config)#ipv6 mld explicit-tracking
Use the no version to disable explicit host tracking on the interface.
Enable explicit host tracking on the interface with the capability of being automatically disabled if MLD V1 hosts are detected on the MLD V2 interface. The router turns off explicit host tracking for the group when MLD V1 host reports are received for the group on the MLD V2 interface.
host1(config)#ipv6 mld explicit-tracking disable-if-mld-v1-detected
Use the no version with the disable-if-mld-detected keyword to revert to the default explicit host tracking behavior.

Disabling and Removing MLD

You can disable and reenable MLD on the virtual router. You can also remove MLD from the virtual router and re-create it on the virtual router.

To disable and enable MLD on a virtual router:

Disable MLD on a virtual router.
host1(config)#virtual-router boston host1:boston(config)#router mld host1:boston(config-router)#mld disable
Use the no version to enable MLD on a virtual router.
Create and enable MLD on a virtual router.
- Using the router mld command:
  host1(config)#virtual-router boston host1:boston(config)#router mld
  Use the no version to delete MLD and MLD proxy from the virtual router.
- Using the ipv6 router mld command:
  host1(config)#virtual-router boston host1:boston(config)#ipv6 router mld
  Use the no version to delete MLD and MLD proxy from the virtual router.