Example for Configuring MLD SSM Mapping

If a host's MLD version cannot be upgraded to MLDv2, configure MLD Source-Specific Multicast (SSM) mapping to implement version compatibility between a multicast device (running a higher MLD version) and user hosts (running a lower MLD version) and enable the multicast device to provide SSM services for the user hosts. The user hosts can then receive multicast data from a specified source.

Networking Requirements

On the IPv6 multicast network shown in Figure 1, PIM-SM is run and the SSM mode is configured. MLDv2 is run on the interface connecting the router to the receiver and MLDv1 is run on the receiver. The MLD version on the receiver is unable to be upgraded to MLDv2.

The SSM group address range is set to FF31::/32, and Sources 1, 2, and 3 all send IPv6 multicast data to multicast groups in this range. The receiver requires IPv6 multicast data only from Sources 1 and 3. To meet this requirement, configure MLD SSM mapping.

Figure 1 Configuring MLD SSM mapping

Device

Interface

IP Address

Device A

GE 0/1/0

2001:db8:5::2/64

GE0/1/8

2001:db8:1::1/64

GE0/1/16

2001:db8:3::1/64

DeviceB

GE 0/1/0

2001:db8:6::2/64

GE0/1/8

2001:db8:1::2/64

GE0/1/16

2001:db8:2::1/64

DeviceC

GE 0/1/0

2001:db8:7::2/64

GE0/1/8

2001:db8:4::1/64

GE0/1/16

2001:db8:2::2/64

DeviceD

GE 0/1/0

2001:db8:8::2/64

GE0/1/8

2001:db8:4::2/64

GE0/1/16

2001:db8:3::2/64

Precautions

When configuring MLD SSM mapping, note the following precautions:

  • IPv6 PIM-SM must be enabled before MLD is enabled.

  • The SSM group address ranges set on all routers in the IPv6 PIM-SM domain must be identical.

  • To make SSM source-group address mapping entries take effect, you must enable SSM mapping first.

Configuration Roadmap

The configuration roadmap is as follows:

  1. Configure an IPv6 address for each router interface and configure a unicast routing protocol.

  2. Enable IPv6 multicast routing on all routers.

  3. Enable IPv6 PIM-SM on all router interfaces.

  4. Enable MLD and SSM mapping on interfaces connecting routers to receivers.

  5. Set the SSM group address range on all routers in the IPv6 PIM-SM domain.

  6. Configure SSM mapping rules on routers connected to receivers.

Data Preparation

To complete the configuration, you need the following data:

  • SSM group address range

  • IPv6 addresses of Sources 1 and 3

Procedure

  1. Configure an IPv6 address for each router interface and a unicast routing protocol. For configuration details, see Configuration Files in this section.
  2. Enable IPv6 multicast routing on each router and IPv6 PIM-SM on each router interface.

    # Configure Device D. The configurations of Device A, Device B, and Device C are similar to the configuration of Device D. For configuration details, see Configuration Files in this section.

    [~DeviceD] multicast ipv6 routing-enable
[*DeviceD] interface gigabitethernet 0/1/0
[*DeviceD-GigabitEthernet0/1/0] pim ipv6 sm
[*DeviceD-GigabitEthernet0/1/0] quit
[*DeviceD] interface gigabitethernet 0/1/8
[*DeviceD-GigabitEthernet0/1/8] pim ipv6 sm
[*DeviceD-GigabitEthernet0/1/8] quit
[*DeviceD] interface gigabitethernet 0/1/16
[*DeviceD-GigabitEthernet0/1/16] pim ipv6 sm
[*DeviceD-GigabitEthernet0/1/16] commit
[~DeviceD-GigabitEthernet0/1/16] quit

  3. Enable MLD and SSM mapping on the interface connecting the router to the receiver.

    # Enable MLD and SSM mapping on GE 0/1/0 of Device D.

    [~DeviceD] interface gigabitethernet 0/1/0
[~DeviceD-GigabitEthernet0/1/0] mld enable
[*DeviceD-GigabitEthernet0/1/0] mld version 2
[*DeviceD-GigabitEthernet0/1/0] mld ssm-mapping enable
[*DeviceD-GigabitEthernet0/1/0] commit
[~DeviceD-GigabitEthernet0/1/0] quit

  4. Set the SSM group address range to FF31::/32 on all devices in the IPv6 PIM-SM domain.

    # Configure Device A. The configurations of Device B, Device C, and Device D are similar to the configuration of Device A. For configuration details, see Configuration Files in this section.

    [~DeviceA] acl ipv6 number 2000
[*DeviceA-acl6-basic-2000] rule permit source ff31::/32
[*DeviceA-acl6-basic-2000] quit
[*DeviceA] pim-ipv6
[*DeviceA-pim6] ssm-policy 2000
[*DeviceA-pim6] commit
[~DeviceA-pim6] quit

  5. Configure SSM mapping rules on the router connected to the receiver.

    # On Device D, map the multicast groups in the range of FF31::/32 to Sources 1 and 3.

    [~DeviceD] mld
[*DeviceD-mld] ssm-mapping ff31:: 32 2001:db8:5::1
[*DeviceD-mld] ssm-mapping ff31:: 32 2001:db8:7::1
[*DeviceD-mld] commit
[~DeviceD-mld] quit

  6. Verify the configuration.

    # View information about SSM mapping rules on Device D.

    <DeviceD> display mld ssm-mapping group
MLD SSM-Mapping conversion table of VPN-Instance: public net
 Total 2 entries, 2 entries matched

 00001. (2001:db8:5::1, FF31::)

 00002. (2001:db8:7::1, FF31::)

    The command output shows that the receiver joins group FF31::1. # Run the display mld group ssm-mapping command to view source-group information on router D. The command output is as follows:

    <DeviceD> display mld group ssm-mapping
MLD SSM mapping Interface group report information of VPN-Instance: public net
 GigabitEthernet0/1/0 (2001:db8:8::2):
  Total 1 MLD SSM-Mapping Group reported
   Group Address   Last Reporter   Uptime      Expires
   FF31::1         2001:db8:8::1   00:01:44    00:00:26
<DeviceD> display mld group ssm-mapping verbose
Total entry on this router: 1
Interface group report information of VPN-Instance: public net
 GigabitEthernet0/1/0(FE80::DD:84):
  Total entry on this interface: 1
  Total 1 MLD SSM-Mapping Group reported
   Group: FF31::1
     Uptime: 00:00:13
     Expires: 00:04:07
     Last reporter: FE80::10
     Last-listener-query-counter: 0
     Last-listener-query-timer-expiry: off
     Group mode: exclude
     Version1-host-present-timer-expiry: 00:04:07

    # Run the display pim ipv6 routing-table command to view information about the IPv6 PIM-SM routing table on Device D. The command output is as follows:

    <DeviceD> display pim ipv6 routing-table
VPN-Instance: public net
 Total 0 (*, G) entry; 2 (S, G) entries
 (2001:db8:5::1, FF31::1)
     Protocol: pim-ssm, Flag:SG_RCVR
     UpTime: 00:11:25
     Upstream interface: GigabitEthernet0/1/16, Refresh time: 00:11:25
         Upstream neighbor: 2001:db8:3::1
         RPF prime neighbor: 2001:db8:3::1
     Downstream interface(s) information:
     Total number of downstreams: 1
         1: GigabitEthernet0/1/0
             Protocol: mld, UpTime: 00:11:25, Expires:-
 (2001:db8:7::1, FF31::1)
     Protocol: pim-ssm, Flag:SG_RCVR
     UpTime: 00:11:25
     Upstream interface: GigabitEthernet0/1/8, Refresh time: 00:11:25
         Upstream neighbor: 2001:db8:4::1
         RPF prime neighbor: 2001:db8:4::1
     Downstream interface(s) information:
     Total number of downstreams: 1
         1: GigabitEthernet0/1/0
             Protocol: mld, UpTime: 00:11:25, Expires:-

Configuration Files

  • Device A configuration file

    #
sysname DeviceA
#
multicast ipv6 routing-enable
#
acl ipv6 number 2000
 rule permit source ff31::/32
#
isis 1
 ipv6 enable topology ipv6
 network-entity 10.0000.0000.0001.00
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:5::2/64
 pim ipv6 sm
 isis ipv6 enable 1
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:1::1/64
 pim ipv6 sm
 isis ipv6 enable 1
#
interface GigabitEthernet0/1/16
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:3::1/64
 pim ipv6 sm
 isis ipv6 enable 1
#
pim-ipv6
ssm-policy 2000
#
return

  • Device B configuration file

    #
sysname DeviceB
#
multicast ipv6 routing-enable
#
acl ipv6 number 2000
 rule permit source ff31::/32
#
isis 1
 ipv6 enable topology ipv6
 network-entity 10.0000.0000.0002.00
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:6::2/64
 pim ipv6 sm
 isis ipv6 enable 1
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:1::2
 pim ipv6 sm
 isis ipv6 enable 1
#
interface GigabitEthernet0/1/16
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:2::1/64
 pim ipv6 sm
 isis ipv6 enable 1
#
pim-ipv6
 ssm-policy 2000
#
return

  • Device C configuration file

    #
sysname DeviceC
#
multicast ipv6 routing-enable
#
acl ipv6 number 2000
 rule permit source ff31::/32
#
isis 1
 ipv6 enable topology ipv6
 network-entity 10.0000.0000.0003.00
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:7::2/64
 pim ipv6 sm
 isis ipv6 enable 1
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:4::1/64
 pim ipv6 sm
 isis ipv6 enable 1
#
interface GigabitEthernet0/1/16
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:2::2/64
 pim ipv6 sm
 isis ipv6 enable 1
#
pim-ipv6
 ssm-policy 2000
#
return

  • Device D configuration file

    #
sysname DeviceD
#
multicast ipv6 routing-enable
#
acl ipv6 number 2000
 rule permit source ff31::/32
#
isis 1
 ipv6 enable topology ipv6
 network-entity 10.0000.0000.0004.00
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:8::2/64
 pim ipv6 sm
 mld enable
 mld version 2
 mld ssm-mapping enable
 isis ipv6 enable 1
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:4::2/64
 pim ipv6 sm
 isis ipv6 enable 1
#
interface GigabitEthernet0/1/16
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:3::2/64
 pim ipv6 sm
 isis ipv6 enable 1
#
mld
 ssm-mapping ff31:: 32 2001:db8:5::1
 ssm-mapping ff31:: 32 2001:db8:7::1
#
pim-ipv6
 ssm-policy 2000
#
return
Parent Topic: Configuration Examples for MLD
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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