forward-mode (VBDIF interface view)

Function

The forward-mode loopback command sets the packet forwarding mode to loopback on a VBDIF interface.

The undo forward-mode command restores the default configuration.

By default, the packet forwarding mode is not set to loopback on a VBDIF interface.

Format

forward-mode loopback

undo forward-mode

Parameters

None

Views

VBDIF interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
forwarding	write

Usage Guidelines

Usage Scenario

By default, when a Layer 3 network connects to a PW network through VBDIF interfaces, the following problems exist:

MTU fragmentation is not supported when the PW encapsulation process is used in the downstream direction.
Downstream multicast traffic statistics for a VBDIF interface are statistics on traffic replicated for VBDIF interface's member interfaces.
After the forward-mode loopback command is run to set the packet forwarding mode to loopback, downstream MTU fragmentation is supported on a VBDIF interface and multicast traffic statistics are for a copy of traffic forwarded from the VBDIF interfaces.

Precautions

After the forwarding mode is set to loopback on a VBDIF interface, the interface's forwarding performance deteriorates. Set the forwarding mode as required.

The configuration fails if the following situations are met:

A BD is bound to a VSI.
The igmp-snooping enable command is run in the BD view.
The mpls vpls convergence separate enable command is run in the system view or VSI view.

Example

# Set the packet forwarding mode on a VBDIF interface into loopback.

<HUAWEI> system-view
[~HUAWEI] bridge-domain 10
[*HUAWEI--bd10] quit
[*HUAWEI] interface vbdif 10
[*HUAWEI-Vbdif10] forward-mode loopback