HP 6125G HP 6125G & 6125G/XG Blade Switches IP Multicast Configuration - Page 295

Troubleshooting MLD, No member information on the receiver-side router, Symptom, Analysis, Solution

Page 295 highlights

# Display MLD group information on Switch A. [SwitchA] display mld group Total 1 MLD Group(s). Interface group report information Vlan-interface100(2001::1): Total 1 MLD Groups reported Group Address Last Reporter Uptime ff3e::101 2001::2 00:02:04 Expires 00:01:15 The output shows that the MLD reports sent from the hosts are forwarded to Switch A through the proxy interface, VLAN-interface 100 of Switch B. Troubleshooting MLD No member information on the receiver-side router Symptom When a host sends a message to announce its joining IPv6 multicast group G, no member information of multicast group G exists on the immediate 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. Check that the networking, interface connections, and IP address configuration are correct. Check the interface information with the display mld interface command. If no information is output, the interface is in an abnormal state. This is usually because you have configured the shutdown command on the interface, the interface is not properly connected, or 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, carry out the multicast ipv6 routing-enable command in system view to enable IPv6 multicast routing. In addition, enable MLD on the corresponding interface. 3. You can 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 restrict the host from joining IPv6 multicast group G, the ACL must be modified to allow IPv6 multicast group G to receive report messages. 284

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284
# Display MLD group information on Switch A.
[SwitchA] display mld group
Total 1 MLD Group(s).
Interface group report information
Vlan-interface100(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 Switch A through the proxy
interface, VLAN-interface 100 of Switch B.
Troubleshooting MLD
No member information on the receiver-side router
Symptom
When a host sends a message to announce its joining IPv6 multicast group G, no member information
of multicast group G exists on the immediate 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.
Check that the networking, interface connections, and IP address configuration are correct. Check
the interface information with the
display mld interface
command. If no information is output, the
interface is in an abnormal state. This is usually because you have configured the
shutdown
command on the interface, the interface is not properly connected, or 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, carry out the
multicast ipv6 routing-enable
command in system view to enable IPv6 multicast
routing. In addition, enable MLD on the corresponding interface.
3.
You can 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
restrict the host from joining IPv6 multicast group G, the ACL must be modified to allow IPv6
multicast group G to receive report messages.