Technical Documentation

Enabling MLD Static Group Membership

You can create MLD static group membership to test multicast forwarding without a receiver host. When you enable MLD static group membership, data is forwarded to an interface without that interface receiving membership reports from downstream hosts.

When you configure static groups on an interface on which you want to receive multicast traffic, you can specify the number of static groups to be automatically created.

In this example, you create static group ff02::1:ff05:1a8d.

  1. Configure the static groups to be created by including the static statement and group statement and specifying the IPv6 multicast address of the group to be created.
    user@host# set protocols mld interface fe-0/1/2 static group ff02::1:ff05:1a8d
  2. After you commit the configuration, use the show configuration protocol mld command to verify the MLD protocol configuration.
    user@host> show configuration protocol mld
    interface fe-0/1/2.0 {static {group ff02::1:ff05:1a8d;}}
  3. After you have committed the configuration and the source is sending traffic, use the show mld group command to verify that static group ff02::1:ff05:1a8 has been created.

    user@host> show mld group
    Interface: fe-0/1/2
    Group: ff02::1:ff05:1a8d 
    Group mode: Include
    Source: fe80::2e0:81ff:fe05:1a8d
    Last reported by: Local
    Timeout: 0 Type: Static
    

    Note: You must specify a unique address for each group.

When you create MLD static group membership to test multicast forwarding on an interface on which you want to receive multicast traffic, you can specify that a number of static groups be automatically created. This is useful when you want to test forwarding to multiple receivers without needing to configure each receiver separately.

In this example, you create three groups.

  1. Configure the number of static groups to be created by including the group-count statement and specifying the number of groups to be created.
    user@host# set protocols mld interface fe-0/1/2 static group ff02::1:ff05:1a8d group-count 3
  2. After you commit the configuration, use the show configuration protocol mld command to verify the MLD protocol configuration.
    user@host> show configuration protocol mld
    interface fe-0/1/2.0 {static {group ff02::1:ff05:1a8d {group-count 3;}}}
  3. After you have committed the configuration and the source is sending traffic, use the show mld group command to verify that static groups ff02::1:ff05:1a8d, ff02::1:ff05:1a8e, and ff02::1:ff05:1a8f have been created.

    user@host> show mld group
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8e
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8f
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    

When you configure static groups on an interface on which you want to receive multicast traffic and you specify the number of static groups to be automatically created, you can also configure the group address to be automatically incremented by some number of addresses.

In this example, you create three groups and increase the group address by an increment of two for each group.

  1. Configure the group address increment by including the group-increment statement and specifying the number by which the address should be incremented for each group. The increment is specified in a format similar to an IPv6 address.
    user@host# set protocols mld interface fe-0/1/2 static group ff02::1:ff05:1a8d group-count 3 group-increment ::2
  2. After you commit the configuration, use the show configuration protocol mld command to verify the MLD protocol configuration.
    user@host> show configuration protocol mld
    interface fe-0/1/2.0 {static {group ff02::1:ff05:1a8d {group-increment ::2;group-count 3;}}}
  3. After you have committed the configuration and the source is sending traffic, use the show mld group command to verify that static groups ff02::1:ff05:1a8d, ff02::1:ff05:1a8f, and ff02::1:ff05:1a91 have been created.

    user@host> show mld group
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8f
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a91
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    

When you configure static groups on an interface on which you want to receive multicast traffic and your network is operating in source-specific multicast (SSM) mode, you can specify the multicast source address to be accepted.

If you specify a group address in the SSM range, you must also specify a source.

If a source address is specified in a multicast group that is statically configured, the MLD version must be set to MLDv2 on the interface. MLDv1 is the default value.

In this example, you create group ff02::1:ff05:1a8d and accept IPv6 address fe80::2e0:81ff:fe05:1a8d as the only source.

  1. Configure the source address by including the source statement and specifying the IPv6 address of the source host.
    user@host# set protocolsmld interface fe-0/1/2 static group ff02::1:ff05:1a8d source fe80::2e0:81ff:fe05:1a8d
  2. After you commit the configuration, use the show configuration protocol mld command to verify the MLD protocol configuration.
    user@host> show configuration protocol mld
    interface fe-0/1/2.0 {static {group ff02::1:ff05:1a8d {source fe80::2e0:81ff:fe05:1a8d;}}}
  3. After you have committed the configuration and the source is sending traffic, use the show mld group command to verify that static group ff02::1:ff05:1a8d has been created and that source fe80::2e0:81ff:fe05:1a8d has been accepted.

    user@host> show mld group
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    

When you configure static groups on an interface on which you want to receive multicast traffic, you can specify a number of multicast sources to be automatically accepted.

In this example, you create static group ff02::1:ff05:1a8d and accept fe80::2e0:81ff:fe05:1a8d, fe80::2e0:81ff:fe05:1a8e, and fe80::2e0:81ff:fe05:1a8f as the source addresses.

  1. Configure the number of multicast source addresses to be accepted by including the source-count statement and specifying the number of sources to be accepted.
    user@host# set protocols mld interface fe-0/1/2 static group ff02::1:ff05:1a8d source fe80::2e0:81ff:fe05:1a8d source-count 3
  2. After you commit the configuration, use the show configuration protocol mld command to verify the MLD protocol configuration.
    user@host> show configuration protocol mld
    interface fe-0/1/2.0 {static {group ff02::1:ff05:1a8d {source fe80::2e0:81ff:fe05:1a8d {source-count 3;}}}}
  3. After you have committed the configuration and the source is sending traffic, use the show mld group command to verify that static group ff02::1:ff05:1a8d has been created and that sources fe80::2e0:81ff:fe05:1a8d, fe80::2e0:81ff:fe05:1a8e, and fe80::2e0:81ff:fe05:1a8f have been accepted.

    user@host> show mld group
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a8e
             Last reported by: Local
             Timeout: 0 Type: Static
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a8f
             Last reported by: Local
             Timeout: 0 Type: Static
    

When you configure static groups on an interface on which you want to receive multicast traffic, and specify a number of multicast sources to be automatically accepted, you can also specify the number by which the address should be incremented for each source accepted.

In this example, you create static group ff02::1:ff05:1a8d and accept fe80::2e0:81ff:fe05:1a8d, fe80::2e0:81ff:fe05:1a8f, and fe80::2e0:81ff:fe05:1a91 as the sources.

  1. Configure the number of multicast source addresses to be accepted by including the source-increment statement and specifying the number of sources to be accepted.
    user@host# set protocols mld interface fe-0/1/2 static group ff02::1:ff05:1a8d source fe80::2e0:81ff:fe05:1a8d source-count 3 source-increment ::2
  2. After you commit the configuration, use the show configuration protocol mld command to verify the MLD protocol configuration.
    user@host> show configuration protocol mld
    interface fe-0/1/2.0 {static {group ff02::1:ff05:1a8d {source fe80::2e0:81ff:fe05:1a8d {source-count 3;source-increment ::2;}}}}
  3. After you have committed the configuration and the source is sending traffic, use the show mld group command to verify that static group ff02::1:ff05:1a8d has been created and that sources fe80::2e0:81ff:fe05:1a8d, fe80::2e0:81ff:fe05:1a8f, and fe80::2e0:81ff:fe05:1a91 have been accepted.

    user@host> show mld group
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a8f
             Last reported by: Local
             Timeout: 0 Type: Static
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Source: fe80::2e0:81ff:fe05:1a91
             Last reported by: Local
             Timeout: 0 Type: Static
    
    Interface: fe-0/1/2
    Group: ff02::1:ff05:1a8d
    Group mode: Include
    Source: fe80::2e0:81ff:fe05:1a8d
    Last reported by: Local
    Timeout: 0 Type: Static
    Group: ff02::1:ff05:1a8d
    Group mode: Include
    Source: fe80::2e0:81ff:fe05:1a8f
    Last reported by: Local
    Timeout: 0 Type: Static
    Group: ff02::1:ff05:1a8d
    Group mode: Include
    Source: fe80::2e0:81ff:fe05:1a91
    Last reported by: Local
    Timeout: 0 Type: Static

When you configure static groups on an interface on which you want to receive multicast traffic and your network is operating in source-specific multicast (SSM) mode, you can specify that certain multicast source addresses be excluded.

By default the multicast source address configured in a static group operates in include mode. In include mode the multicast traffic for the group is accepted from the source address configured. You can also configure the static group to operate in exclude mode. In exclude mode the multicast traffic for the group is accepted from any address other than the source address configured.

If a source address is specified in a multicast group that is statically configured, the MLD version must be set to MLDv2 on the interface. MLDv1 is the default value.

In this example, you exclude address fe80::2e0:81ff:fe05:1a8d as a source for group ff02::1:ff05:1a8d.

  1. Configure a multicast static group to operate in exclude mode by including the exclude statement and specifying the IPv6 source address that should be excluded.
    user@host# set protocols mld interface fe-0/1/2 static group ff02::1:ff05:1a8d exclude source fe80::2e0:81ff:fe05:1a8d
  2. After you commit the configuration, use the show configuration protocol mld command to verify the MLD protocol configuration.
    user@host> show configuration protocol mld
    interface fe-0/1/2.0 {static {group ff02::1:ff05:1a8d {exclude;source fe80::2e0:81ff:fe05:1a8d;}}}
  3. After you have committed the configuration and the source is sending traffic, use the show mld group detail command to verify that static group ff02::1:ff05:1a8d has been created and that the static group is operating in exclude mode.

    user@host> show mld group detail
    Interface: fe-0/1/2
         Group: ff02::1:ff05:1a8d
             Group mode: Exclude
             Source: fe80::2e0:81ff:fe05:1a8d
             Last reported by: Local
             Timeout: 0 Type: Static
         

Similar configuration is available for IPv4 multicast traffic using the IGMP protocol.


Published: 2010-04-16