Configuring IPv6 multicast group replacement
Under special circumstances, the number of IPv6 multicast groups that a switch or a port joins might exceed the upper limit. In addition, in some specific applications, an IPv6 multicast group newly joined on the switch must replace an existing IPv6 multicast group automatically. A typical example is channel switching. Namely, by joining the new multicast group, a user automatically switches from the current IPv6 multicast group to the new one.
To address this situation, enable the IPv6 multicast group replacement function on the switch or certain ports. When the number of IPv6 multicast groups that a switch or a port has joined exceeds the limit, one of the following occurs:
If the IPv6 multicast group replacement is enabled, the newly joined IPv6 multicast group automatically replaces an existing IPv6 multicast group with the lowest IPv6 address.
If the IPv6 multicast group replacement is not enabled, new MLD reports will be automatically discarded.
Configuring IPv6 multicast group replacement globally
Follow these steps to configure IPv6 multicast group replacement globally:
To do... | Use the command... | Remarks |
|---|---|---|
Enter system view | system-view | — |
Enter MLD snooping view | mld-snooping | — |
Enable IPv6 multicast group replacement | overflow-replace [ vlan vlan-list ] | Required Disabled by default |
Configuring IPv6 multicast group replacement on a port or a group of ports
Follow these steps to configure IPv6 multicast group replacement on a port or a group of ports:
To do... | Use the command... | Remarks |
|---|---|---|
Enter system view | system-view | — |
Enter Ethernet interface/Layer 2 aggregate interface view or port group view | interface interface-type interface-number | Required Use either approach |
port-group manual port-group-name | ||
Enable IPv6 multicast group replacement | mld-snooping overflow-replace [ vlan vlan-list ] | Required Disabled by default |
![[CAUTION: ]](images/caution.png) | CAUTION: Be sure to configure the maximum number of IPv6 multicast groups allowed on a port before enabling IPv6 multicast group replacement. Otherwise, the IPv6 multicast group replacement functionality will not take effect. For more information about the maximum number of IPv6 groups that a port can join, see "Configuring maximum multicast groups that a port can join." | |