H3C S12500R Switch Router Series
MLD Snooping Configuration Examples

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The information in this document is subject to change without notice.

 

Contents

Introduction· 1

Prerequisites· 1

Example: Configuring IPv6 multicast group policies· 1

Network configuration· 1

Analysis· 2

Software versions used· 2

Restrictions and guidelines· 2

Procedures· 2

Verifying the configuration· 3

Configuration files· 3

Example: Configuring MLD snooping static ports· 4

Network configuration· 4

Analysis· 5

Software versions used· 5

Restrictions and guidelines· 5

Procedures· 6

Verifying the configuration· 7

Configuration files· 8

Related documentation· 9

Introduction

This document introduces MLD snooping configuration examples.

Prerequisites

This document is not restricted to specific software or hardware versions.

The configuration examples in this document were created and verified in a lab environment, and all the devices were started with the factory default configuration. When you are working on a live network, make sure you understand the potential impact of every command on your network.

This document assumes that you have basic knowledge of MLD snooping.

Example: Configuring IPv6 multicast group policies

Network configuration

As shown in Figure 1:

·     Router A runs MLDv1 and acts as the MLD querier in VLAN 100.

·     Device A runs MLDv1 snooping.

Configure IPv6 multicast group policies on Device A so that Host A and Host B receive only the IPv6 multicast data addressed to IPv6 multicast group FF1E::101.

Figure 1 Network diagram

 

Analysis

To meet the network requirements, you must perform the following tasks:

·     To prevent Device A from flooding MLDv1 packets in VLAN 100, specify MLD snooping version 2 in VLAN 100. By default, MLDv1 snooping runs on the device. MLDv1 snooping processes only MLDv1 packets and floods MLDv2 packets in a VLAN.

·     To prevent receiver hosts in VLAN 100 from receiving IPv6 multicast data addressed to other groups, enable dropping unknown IPv6 multicast data in VLAN 100.

·     To configure an IPv6 multicast group policy, specify an IPv6 basic ACL and create ACL rules to define the groups you want the receiver hosts to join.

Software versions used

This configuration example was created and verified on Release 3606.

Restrictions and guidelines

You must globally enable MLD snooping in system view before you enable MLD snooping for a VLAN in VLAN view.

IPv6 multicast group filtering denies all groups if the specified ACL does not exist or the ACL does not have any rules.

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

In this example, interfaces must operate in Layer 2 mode. By default, physical interfaces on the device are operating at Layer 3 mode. To configure an interface to operate in Layer 2 mode, use the port link-mode command to change the link mode of that interface.

Procedures

1.     Assign an IPv6 address and prefix length to each interface on the routers in the IPv6 PIM-DM domain. (Details not shown.)

2.     Configure an IPv6 unicast routing protocol on the routers in the IPv6 PIM-DM domain. (Details not shown.)

3.     Enable IPv6 multicast routing globally on the routers in the IPv6 PIM-DM domain. (Details not shown.)

4.     Enable IPv6 PIM-DM for the interfaces through which routers connects with each other on the routers in the IPv6 PIM-DM domain. (Details not shown.)

5.     Configure Device A:

# Enable MLD snooping globally.

<DeviceA> system-view

[DeviceA] mld-snooping

[DeviceA-mld-snooping] quit

# Create VLAN 100, and assign HundredGigE 1/0/1 through HundredGigE 1/0/4 to this VLAN.

[DeviceA] vlan 100

[DeviceA-vlan100] port hundredgige 1/0/1 to hundredgige 1/0/4

# In VLAN 100, enable MLD snooping, specify MLD snooping version 2, and dropping unknown IPv6 multicast data for VLAN 100.

[DeviceA-vlan100] mld-snooping enable

[DeviceA-vlan100] mld-snooping version 2

[DeviceA-vlan100] mld-snooping drop-unknown

[DeviceA-vlan100] quit

# Configure an IPv6 multicast group policy for VLAN 100 so that receiver hosts in this VLAN can join only IPv6 multicast group FF1E::101.

[DeviceA] acl ipv6 basic 2001

[DeviceA-acl-ipv6-basic-2001] rule permit source ff1e::101 128

[DeviceA-acl-ipv6-basic-2001] quit

[DeviceA] mld-snooping

[DeviceA–mld-snooping] group-policy 2001 vlan 100

[DeviceA–mld-snooping] quit

Verifying the configuration

# Send MLD reports from Host A and Host B to join IPv6 multicast groups FF1E::101 and FF1E::202. (Details not shown.)

# Send IPv6 multicast data from the source to IPv6 multicast groups FF1E::101 and FF1E::202. (Details not shown.)

# Display dynamic MLD snooping group entries for VLAN 100 on Device A.

[DeviceA] display mld-snooping group vlan 100

Total 1 entries.

 

VLAN 100: Total 1 entries.

  (::, FF1E::101)

    Host ports (2 in total):

      HGE1/0/3                                     (00:03:23)

      HGE1/0/4                                     (00:04:10)

The output shows that Host A and Host B have joined IPv6 multicast group FF1E::101 through member ports HundredGigE 1/0/4 and HundredGigE 1/0/3. Host A and Host B do not join IPv6 multicast group FF1E::202. The IPv6 multicast group policy has taken effect.

Configuration files

Device A:

#

acl ipv6 number 2001

 rule 0 permit source FF1E::101/128

#

mld-snooping

 group-policy 2001 vlan 100

#

vlan 100

 mld-snooping enable

 mld-snooping version 2

 mld-snooping drop-unknown

#

interface HundredGigE1/0/1

 port link-mode bridge

 port access vlan 100

#

interface HundredGigE1/0/2

 port link-mode bridge

 port access vlan 100

#

interface HundredGigE1/0/3

 port link-mode bridge

 port access vlan 100

#

interface HundredGigE1/0/4

 port link-mode bridge

 port access vlan 100

#

Example: Configuring MLD snooping static ports

Network configuration

As shown in Figure 2:

·     All devices in VLAN 100 run MLD snooping.

·     Router A runs MLDv1 and acts as the MLD querier.

·     STP runs in VLAN 100. The direct route between Device A and Device B or the route from Device A to Device B with Device C as the intermediate device is blocked to avoid loops.

Configure MLD snooping static ports to meet the following requirements:

·     IPv6 multicast data uninterruptedly flows to Host A and Host B after a link switchover occurs between Device A and Device B.

·     Host A and Host B permanently receive the IPv6 multicast data addressed to IPv6 multicast group FF1E::101.

Figure 2 Network diagram

 

Analysis

To meet the network requirements, you must perform the following tasks:

·     By default, when a link switchover occurs, multicast data can flow along the new link after a minimum of one MLD query-response cycle. Multicast delivery is interrupted during this process.

Configure HundredGigE 1/0/2 and HundredGigE 1/0/3 on Device A, HundredGigE 1/0/4 on Device B, and HundredGigE 1/0/2 on Device C as static router ports. Then, IPv6 multicast data will always be forwarded to these ports, and multicast delivery is uninterrupted.

·     Configure HundredGigE 1/0/2 and HundredGigE 1/0/3 on Device B as static member ports of IPv6 multicast group FF1E::101. Then, IPv6 multicast data for the group will always be forwarded out of these ports, and Host A and Host B can always receiver the data.

Software versions used

This configuration example was created and verified on Release 3606.

Restrictions and guidelines

You must globally enable MLD snooping in system view before you enable MLD snooping for a VLAN in VLAN view.

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

In this example, interfaces must operate in Layer 2 mode. By default, physical interfaces on the device are operating at Layer 3 mode. To configure an interface to operate in Layer 2 mode, use the port link-mode command to change the link mode of that interface.

Procedures

1.     Assign an IPv6 address and prefix length to each interface on the routers in the IPv6 PIM-DM domain. (Details not shown.)

2.     Configure an IPv6 unicast routing protocol on the routers in the IPv6 PIM-DM domain. (Details not shown.)

3.     Enable IPv6 multicast routing globally on the routers in the IPv6 PIM-DM domain. (Details not shown.)

4.     Enable IPv6 PIM-DM for the interfaces through which routers connects with each other on the routers in the IPv6 PIM-DM domain. (Details not shown.)

5.     Configure Device A:

# Enable MLD snooping globally.

<DeviceA> system-view

[DeviceA] mld-snooping

[DeviceA-mld-snooping] quit

# Create VLAN 100, assign HundredGigE 1/0/1 through HundredGigE 1/0/3 to this VLAN, and enable MLD snooping for this VLAN.

[DeviceA] vlan 100

[DeviceA-vlan100] port hundredgige 1/0/1 to hundredgige 1/0/3

[DeviceA-vlan100] mld-snooping enable

[DeviceA-vlan100] quit

# Configure HundredGigE 1/0/2 and HundredGigE 1/0/3 as static router ports.

[DeviceA] interface hundredgige 1/0/2

[DeviceA-HundredGigE1/0/2] mld-snooping static-router-port vlan 100

[DeviceA-HundredGigE1/0/2] quit

[DeviceA] interface hundredgige 1/0/3

[DeviceA-HundredGigE1/0/3] mld-snooping static-router-port vlan 100

[DeviceA-HundredGigE1/0/3] quit

6.     Configure Device B:

# Enable MLD snooping globally.

<DeviceB> system-view

[DeviceB] mld-snooping

[DeviceB-mld-snooping] quit

# Create VLAN 100, assign HundredGigE 1/0/1 and HundredGigE 1/0/4 to this VLAN, and enable MLD snooping for this VLAN.

[DeviceB] vlan 100

[DeviceB-vlan100] port hundredgige 1/0/1 hundredgige 1/0/4

[DeviceB-vlan100] mld-snooping enable

[DeviceB-vlan100] quit

# Configure HundredGigE 1/0/4 as a static router port.

[DeviceB] interface hundredgige 1/0/4

[DeviceB-HundredGigE1/0/4] mld-snooping static-router-port vlan 100

[DeviceB-HundredGigE1/0/4] quit

# Configure HundredGigE 1/0/2 and HundredGigE 1/0/3 as static member ports for IPv6 multicast group FF1E::101 in VLAN 100.

[DeviceB] interface hundredgige 1/0/2

[DeviceB-HundredGigE1/0/2] mld-snooping static-group ff1e::101 vlan 100

[DeviceB-HundredGigE1/0/2] quit

[DeviceB] interface hundredgige 1/0/3

[DeviceB-HundredGigE1/0/3] mld-snooping static-group ff1e::101 vlan 100

[DeviceB-HundredGigE1/0/3] quit

7.     Configure Device C:

# Enable MLD snooping globally.

<DeviceC> system-view

[DeviceC] mld-snooping

[DeviceC-mld-snooping] quit

# Create VLAN 100, assign HundredGigE 1/0/1 through HundredGigE 1/0/4 to this VLAN, and enable MLD snooping for this VLAN.

[DeviceC] vlan 100

[DeviceC-vlan100] port hundredgige 1/0/1 to hundredgige 1/0/4

[DeviceC-vlan100] mld-snooping enable

[DeviceC-vlan100] quit

# Configure HundredGigE1/0/2 as a static router port in VLAN 100.

[DeviceC] interface hundredgige 1/0/2

[DeviceC-HundredGigE1/0/2] mld-snooping static-router-port vlan 100

[DeviceC-HundredGigE1/0/2] quit

Verifying the configuration

Verify the configuration before hosts join any multicast groups.

# Display static router port information for VLAN 100 on Device A.

[DeviceA] display mld-snooping static-router-port vlan 100

VLAN 100:

  Router ports (2 in total):

    HGE1/0/2

    HGE1/0/3

The output shows that HundredGigE 1/0/2 and HundredGigE 1/0/3 on Device A have become static router ports in VLAN 100.

# Display static router port information for VLAN 100 on Device B.

[DeviceB] display mld-snooping static-router-port vlan 100

VLAN 100:

  Router ports (1 in total):

    HGE1/0/4

The output shows that HundredGigE 1/0/4 on Device B has become a static router port in VLAN 100.

# Display static MLD snooping group entries for VLAN 100 on Device B.

[DeviceB] display mld-snooping static-group vlan 100

Total 1 entries.

 

VLAN 100: Total 1 entries.

  (::, FF1E::101)

    Host ports (2 in total):

      HGE1/0/2

      HGE1/0/3

The output shows that HundredGigE 1/0/2 and HundredGigE 1/0/3 on Device B have become static member ports of IPv6 multicast group FF1E::101 in VLAN 100.

# Display static router port information for VLAN 100 on Device C.

[DeviceC] display mld-snooping static-router-port vlan 100

VLAN 100:

  Router ports (1 in total):

    HGE1/0/2

The output shows that HundredGigE 1/0/2 on Device C has become a static router port in VLAN 100.

Configuration files

·     Device A:

#

mld-snooping

#

vlan 100

 mld-snooping enable

#

interface HundredGigE1/0/1

 port link-mode bridge

 port access vlan 100

#

interface HundredGigE1/0/2

 port link-mode bridge

 port access vlan 100

 mld-snooping static-router-port vlan 100

#

interface HundredGigE1/0/3

 port link-mode bridge

 port access vlan 100

 mld-snooping static-router-port vlan 100

#

interface HundredGigE1/0/4

 port link-mode bridge

 port access vlan 100

#

·     Device B:

#

mld-snooping

#

vlan 100

 mld-snooping enable

#

interface HundredGigE1/0/1

 port link-mode bridge

 port access vlan 100

#

interface HundredGigE1/0/2

 port link-mode bridge

 port access vlan 100

 mld-snooping static-group FF1E::101 vlan 100

#

interface HundredGigE1/0/3

 port link-mode bridge

 port access vlan 100

 mld-snooping static-group FF1E::101 vlan 100

#

interface HundredGigE1/0/4

 port link-mode bridge

 port access vlan 100

 mld-snooping static-router-port vlan 100

#

·     Device C:

#

mld-snooping

#

vlan 100

 mld-snooping enable

#

interface HundredGigE1/0/1

 port link-mode bridge

 port access vlan 100

#

interface HundredGigE1/0/2

 port link-mode bridge

 port access vlan 100

 mld-snooping static-router-port vlan 100

#

interface HundredGigE1/0/3

 port link-mode bridge

 port access vlan 100

#

interface HundredGigE1/0/4

 port link-mode bridge

 port access vlan 100

#

Related documentation

·     H3C S12500R Switch Router Series IP Multicast Command Reference-R3606

·     H3C S12500R Switch Router Series IP Multicast Configuration Guide-R3606