294
Current MLD version is 1
Multicast routing on this interface: enabled
Require-router-alert: disabled
# Display MLD group information on Router A.
[RouterA] display mld group
Total 1 MLD Group(s).
Interface group report information
Ethernet1/1(2001::1):
Total 1 MLD Groups reported
Group Address Last Reporter Uptime Expires
ff3e::101 2001::2 00:02:04 00:01:15
The output shows that the MLD reports sent from the hosts are forwarded to Router A through the proxy
interface, Ethernet 1/1 of Router B.
Troubleshooting MLD
This section describes common MLD problems and how to troubleshoot them.
No member information exists on the receiver-side router
Symptom
When a host sends a message to announce its intention to join the IPv6 multicast group G, no member
information of multicast group G exists on the intermediate router.
Analysis
•
The correctness of networking and interface connections and whether the protocol layer of the
interface is up directly affect the generation of IPv6 group member information.
•
IPv6 multicast routing must be enabled on the router and MLD must be enabled on the interface
connecting to the host.
•
If the MLD version on the router interface is lower than that on the host, the router will not be able
to recognize the MLD report from the host.
•
If the
mld group-policy
command has been configured on an interface, the interface cannot receive
report messages that fail to pass filtering.
Solution
1.
Use the
display mld interface
command to verify that the networking, interface connections, and IP
address configuration are correct. If no information is output, the interface is in an abnormal state.
The reason is that you have configured the
shutdown
command on the interface, that the interface
is not correctly connected, or that the IPv6 address configuration is not correctly done.
2.
Use the
display current-configuration
command to verify that the IPv6 multicast routing is enabled.
If not, use the
multicast ipv6 routing-enable
command in system view to enable IPv6 multicast
routing. In addition, enable MLD on the corresponding interface.
3.
Use the
display mld interface
command to verify that the MLD version on the interface is lower than
that on the host.
4.
Use the
display current-configuration interface
command to verify that no ACL rule has been
configured to restrict the host from joining IPv6 multicast group G. If an IPv6 ACL is configured to