32.2.4 Checking MLD info

The following are the types of information you can check in the IPv6 multicast routing information for the Switch when the MLD functionality is set.

<Structure of this section>

(1) Interface information

The following describes the checking that is performed by executing the show ipv6 mld interface command:

Check the interfaces displayed in the Interface field. MLD is running on the displayed interfaces. If the expected interface is not displayed, check the mld configuration setting. In addition, check whether a failure has occurred on the interface.
Check the Group Count value (number of groups hosts have joined) for the target interface. If the value is 0, either groups hosts have joined might not exist, or the group member hosts might not advertise MLD-Report. Check the hosts.
Check whether the version displayed in the Version field allows connection with the host used by the interface.

If a code is displayed in the Notice field, MLD packets have been discarded. Use the code to determine why the packets were discarded.

Figure 32-15: Result of executing show ipv6 mld interface command
> show ipv6 mld interface Date 20XX/04/10 15:10:00 UTC Total: 10 Interfaces Interface Version Flags Querier Expires Group Count Notice VLAN0001 1 S fe80::10:87ff:2959 02:30 4 L VLAN0003 2 fe80::10:87ff:2959 01:30 2 VLAN0004 (2) fe80::10:87ff:2959 - 5 QR VLAN0005 1 fe80::1234 01:00 3 Q VLAN0006 1 fe80::2592 02:30 6 (Omitted below)

Figure 32-15: Result of executing show ipv6 mld interface command

> show ipv6 mld interface
Date 20XX/04/10 15:10:00 UTC
Total: 10 Interfaces
Interface   Version   Flags  Querier             Expires  Group Count  Notice
VLAN0001       1      S      fe80::10:87ff:2959   02:30             4  L
VLAN0003       2             fe80::10:87ff:2959   01:30             2
VLAN0004      (2)            fe80::10:87ff:2959     -               5   QR
VLAN0005       1             fe80::1234           01:00             3   Q
VLAN0006       1             fe80::2592           02:30             6
(Omitted below)

(2) Group information

Execute the show ipv6 mld group command and check the groups displayed in the Group Address field. If there are none, check for the following:

The group members (hosts) might not advertise MLD-Report. Check the hosts.
Check the version of the MLD interfaces for the Switch and for each host, and make sure that the Switch can connect to the hosts.

If hosts ignore MLDv2 Query, MLDv2 cannot be used. Set the MLD version of the interface to 1.

Figure 32-16: Result of executing show ipv6 mld group command
> show ipv6 mld group brief Date 20XX/08/01 15:20:00 UTC Total: 20 groups Group Address Interface Version Mode Source Count ff15::100::50 VLAN0001 1 EXCLUDE 9 ff15::100::60 VLAN0003 2 INCLUDE 2 ff15::200::1 VLAN0003 1 EXCLUDE 0 ff15::200::2 VLAN0004 2 EXCLUDE 1 (Omitted below)

Figure 32-16: Result of executing show ipv6 mld group command

> show ipv6 mld group brief
Date 20XX/08/01 15:20:00 UTC
Total: 20 groups
Group Address   Interface       Version  Mode      Source Count
ff15::100::50   VLAN0001           1     EXCLUDE              9
ff15::100::60   VLAN0003           2     INCLUDE              2
ff15::200::1    VLAN0003           1     EXCLUDE              0
ff15::200::2    VLAN0004           2     EXCLUDE              1
(Omitted below)