flow-label (VSI-LDP view)

Function

The flow-label command enables flow label-based load balancing for an VSI.

The undo flow-label command disables flow label-based load balancing of an VSI.

By default, flow label-based load balancing for an VSI is disabled.

Only the S5720-HI, S5730-HI, S5731-H, S5731S-H, S5732-H, S6720-HI, S6730S-H, and S6730-H support this command.

Format

flow-label { both | send | receive } [ static ]

undo flow-label [ { both | send | receive } [ static ] ]

Parameters

Parameter	Description	Value
both	Enables flow label-based load balancing for outgoing traffic and incoming traffic.	-
send	Enables flow label-based load balancing for outgoing traffic.	-
receive	Enables flow label-based load balancing for incoming traffic.	-
static	Statically configures flow label-based load balancing. For dynamic PWs, if static is not configured, the flow label-based load balancing capability of the local end is negotiated by the remote end. For static PWs, the flow label-based load balancing capability is statically configured, irrespective of whether static is configured.	-

Views

VSI-LDP view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

When multiple links exist between P devices on a PW, to improve L2VPN traffic forwarding efficiency and ease the forwarding burden on P devices, run the flow-label command to configure flow label-based load balancing. After flow label-based load balancing is enabled on a PE, the PE adds different flow labels for different L2VPN data flows to distinguish the data flows. After a P device receives a data packet carrying a flow label, it selects a forwarding path based on the flow label in the data packet. This processing implements load balancing.

To enable flow label-based load balancing for all PWs in an VSI, run the flow-label command in the VSI-LDP view.

Prerequisites

MPLS L2VPN has been enabled.

Precautions

Flow label-based load balancing can be enabled only when any of the following conditions is true:

The receive parameter is configured on the local PE, and the send parameter is configured on the remote PE.
The send parameter is configured on the local PE, and the receive parameter is configured on the remote PE.
Both the send and receive parameters are configured on the local and remote PEs.

If the static flow label-based load balancing configuration does not match on both ends, the device discards packets carrying a flow label, causing packet loss.

Example

# Enable flow label-based load balancing for Martini VPLS.

<HUAWEI> system-view
[HUAWEI] vsi 1 static
[HUAWEI-vsi-1] pwsignal ldp
[HUAWEI-vsi-1-ldp] flow-label both