The mld prompt-leave command enables the fast leave function on an interface. This function enables an MLD querier to delete MLD entries immediately after receiving Multicast Listener Done messages from group members, without sending Multicast Address Specific Query messages or Multicast Address and Source Specific Query messages.
The undo mld prompt-leave command disables fast leave on an interface.
By default, an MLD querier sends a Multicast Address Specific Query message or Multicast Address and Source Specific Query message after receiving a Multicast Listener Done message for a specific multicast group.
| Parameter | Description | Value |
|---|---|---|
| group-policy | Specifies an MLD multicast group policy. If this
parameter is specified, the fast leave function takes effect only
for multicast groups specified in the policy. When specifying this
parameter, ensure that the referenced ACL6 has been configured. The
interface filters Multicast Listener Done messages on the interface
based on the ACL6.
If this parameter is not specified, the fast leave function takes effect for all multicast groups. |
- |
| acl6-number | Specifies the number of a basic ACL6 or an advanced ACL6. This ACL6 defines the range of multicast groups. | The number of a basic ACL6 is an integer that ranges from 2000 to 2999. The number of an advanced ACL6 is an integer that ranges from 3000 to 3999. |
GE interface view, XGE interface view, MultiGE interface view, 25GE interface view, 40GE interface view, 100GE interface view, Eth-Trunk interface view, VLANIF interface view, loopback interface view
Usage Scenario
In some scenarios, an interface on the MLD querier connects to only one receiver host. If the host frequently switches between multiple multicast groups, you can configure fast leave on the interface of the querier so that the interface can quickly respond to Multicast Listener Done messages sent from the host. After fast leave is configured, the querier does not send a Multicast Address Specific Query message or Multicast Address and Source Specific Query message after receiving a Multicast Listener Done message. Instead, the querier directly notifies the upstream multicast device that the host has left the multicast group. The fast leave function reduces delay in response to Multicast Listener Done messages and saves network bandwidth.
Prerequisites
Layer 3 IPv6 multicast has been enabled using the multicast ipv6 routing-enable command in the system view.
Precautions
When you run the rule command in the view of a basic ACL6, set source to the address range of multicast groups that hosts can fast leave.
When you run the rule command in the view of an advanced ACL6, set source to the multicast source address and destination to the range of multicast groups that hosts can fast leave.
# Configure fast leave on VLANIF100.
<HUAWEI> system-view [HUAWEI] multicast ipv6 routing-enable [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] mld prompt-leave
<HUAWEI> system-view [HUAWEI] multicast ipv6 routing-enable [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] undo portswitch [HUAWEI-GigabitEthernet0/0/1] mld prompt-leave