multicast copy by-vlan

Function

The multicast copy by-vlan command enables multicast replication by interface + VLAN on a BAS interface.

The undo multicast copy by-vlan command restores the default configuration.

By default, multicast replication by interface + VLAN is disabled, and multicast replication by interface is used.

Format

multicast copy by-vlan

undo multicast copy by-vlan

Parameters

None

Views

10GE interface view, BAS interface view, Eth-Trunk interface view, GE optical interface view, GE electrical interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mcast-base	write

Usage Guidelines

Usage Scenario

In a scenario where multiple users order a multicast program through the same interface and VLAN and MLD snooping is enabled on the downstream Layer 2 device, after multicast replication by interface + VLAN is configured, the BRAS replicates only one copy of a multicast traffic flow for the downstream Layer 2 device. Then, the downstream Layer 2 device replicates multicast data packets based on needs. To enable multicast replication by interface + VLAN, run the multicast copy by-vlan command. This replication mode reduces the burden on the BRAS and the bandwidth consumption. This mode applies to scenarios where user packets carry VLAN tags and inter-VLAN traffic forwarding is not needed.

Prerequisites

IGMP or MLD has been enabled using the igmp enable or mld enable command for the BAS interface. Otherwise, multicast replication by interface + VLAN does not take effect.

Configuration Impact

If you run the multicast copy by-vlan or its undo from on an interface, the users who have gone online from the interface automatically leave multicast groups. As a result, the users' services are interrupted. The users can join multicast groups only after they re-order programs.

Precautions

BAS interfaces support the following types of multicast replication modes, with their priorities being in descending order:

Multicast replication by interface + VLAN: To enable this mode, run the multicast copy by-vlan command in the BAS interface view.
Multicast replication by session: To configure this mode, run the multicast copy by-session command in the BAS interface view.
Multicast replication by multicast VLAN: To configure this mode, run the multicast user-aggregation command in the GE interface view, Eth-Trunk interface view, or Eth-Trunk sub-interface view.
Multicast replication by interface: This is the default mode and does not need to be configured.

In VS mode, this command is supported only by the admin VS.

Example

# Enable multicast replication by interface + VLAN on a BAS interface.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet 0/1/0.1
[*HUAWEI-GigabitEthernet0/1/0.1] bas
[*HUAWEI-GigabitEthernet0/1/0.1] access-type layer2-subscriber
[*HUAWEI-GigabitEthernet0/1/0.1-bas] multicast copy by-vlan