(Optional) Configuring Flow Label-based Load Balancing

Flow label-based load balancing enables L2VPN data flows on a PW to be load-balanced over tunnels between P devices based on flow labels, improving forwarding efficiency.

Context

When multiple links exist between P devices, configure flow label-based load balancing to improve L2VPN traffic forwarding efficiency. After flow label-based load balancing is enabled on a PE, the PE adds different labels for different L2VPN data flows to distinguish them one from the other. After a P device receives a data packet carrying a flow label, it performs the Hash calculation and 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 PWs, run the flow-label command.

Currently, only LDP VPWS, LDP VPLS, and static VPWS and VPLS support flow label-based load balancing.

Procedure

Run system-view
The system view is displayed.
(Optional) Run flow-label hash-fields { l2 | l3 | l4 }
A hash element is configured for flow label load balancing.

This command takes effect only after the PW L2VPN flow label function is enabled in the interface view.
Run interface interface-type interface-number
The AC interface view is displayed.
Run mpls l2vpn flow-label { both | send | receive } [ secondary ] [ static ]
Flow label-based load balancing is enabled for PWs on the interface.
- Flow label-based load balancing can be enabled only when any of the following conditions is met:
  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 secondary is configured, the flow label-based load balancing capability takes effect only for the secondary PW on the interface. If secondary is not configured, the flow label-based load balancing capability takes effect only for the primary PW on the interface.
- If static is configured, the flow label-based load balancing capability is statically configured. The end PEs deliver the flow label-based load balancing capability, irrespective of whether the other end has the capability enabled. 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.
  
  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.
Run commit
The configuration is committed.