forward-mode

Usage Scenario

The prerequisite for selecting the high-performance forwarding mode is that at least one of the inbound and outbound interfaces of the packets resides on the same chip and same board as the VE interface. Otherwise, packets will be forwarded in half-line-rate forwarding mode.

If the traffic rate of a VE interface is lower than half the total bandwidth, using the default configuration is recommended. Disable the high-performance forwarding mode of the VE interface in this situation.

Packets that can be forwarded only in half-line-rate forwarding mode include:

• Anycast packets
• Multicast packets
• Packets to which the padding field is added
  Scenarios where packets can be forwarded only in half-line-rate forwarding mode are as follows:
• Physical interfaces mapping to VE interfaces are configured with TE tunnel bandwidth limits or HQoS services:

1. L2VPN or L3VPN public network tunnels are configured as MPLS TE tunnels and configured with bandwidth limits.
2. MPLS HQoS services are deployed.
3. Network-side HQoS services are deployed.

• VE interfaces are enabled with the Netstream.
  A VE interface and a global VE interface are different:
• A VE interface is a logical Ethernet interface taking effect only on the board the interface resides. Services on the VE interface will be unavailable if the board has a fault.
• A global VE interface is a logical Ethernet interface taking effect on all boards of a device. A global VE can be an L2VE or L3VE. As long as an L2VPN or L3VPN is working properly, the global VE interface can properly send services to a VPN. If the service on a board is not an L2VPN or L3VPN service, reseating the board does not affect services on a global VE interface.
  When half-line-rate forwarding is configured for a VE interface or a global VE interface, HQoS is supported for upstream and downstream traffic.
  When high-performance forwarding is configured for a VE interface or a global VE interface or the forwarding performance of the interface is set between high-performance forwarding and half-line-rate forwarding, HQoS is supported for both upstream and downstream traffic, but the HQoS service has a higher priority.
  When high-performance forwarding is configured for a VE interface or a global VE interface or the forwarding performance of the interface is set between high-performance forwarding and half-line-rate forwarding, HQoS is supported for both upstream and downstream traffic, but the HQoS service has a higher priority.
  If a VE interface is configured to work in high-performance forwarding mode, the HQoS and port queue service may be affected according to different TM service.
• The service which needs to copy TM, (for example, Layer 2 multicast, Layer 3 multicast, and multicast VPN).
  1.If VE interface, traffic inbound interface and traffic outbound interface set in three different boards, these three interfaces all support HQoS and port queue function in inbound and outbound direction.
  2.If VE interface, traffic inbound interface and traffic outbound interface set in one board, VE interface supports HQoS and port queue function in outbound direction, and traffic inbound interface supports HQoS and port queue function in inbound direction and traffic outbound interface does not support HQoS and port queue function in outbound direction.
  3.If VE interface and traffic outbound interface set in one board, and traffic inbound interface set in other board, VE interface supports HQoS and port queue function in outbound direction, and traffic outbound interface does not support HQoS and port queue function in outbound direction.
  4.If VE interface and traffic inbound interface set in one board, and traffic outbound interface set in other board, these three interfaces all support HQoS and port queue function in inbound and outbound direction.
• The service which does not need to copy TM, (for example, unicast).
  1.If VE interface, traffic inbound interface and traffic outbound interface set in three different boards, these three interfaces all support HQoS and port queue function in inbound and outbound direction.
  2.If VE interface, traffic inbound interface and traffic outbound interface set in one board, VE interface supports HQoS and port queue function in inbound direction, and traffic inbound interface does not support HQoS and port queue function in inbound direction and traffic outbound interface supports HQoS and port queue function in outbound direction.
  3.If VE interface and traffic outbound interface set in one board, and traffic inbound interface set in other board, VE interface supports HQoS and port queue function in outbound direction, and traffic outbound interface does not support HQoS and port queue function in outbound direction.
  4.If VE interface and traffic inbound interface set in one board, and traffic outbound interface set in other board, VE interface supports HQoS and port queue function in inbound direction and traffic inbound interface does not support HQoS and port queue function in inbound direction.

Prerequisites

Before running the forward-mode command on a global VE interface, ensure that the global VE interface has been bound to a VE-Group.

Configuration Impact

In half-line-rate forwarding mode, the total bandwidth of the VE interfaces equals half the total bandwidth of the interface board. After you run the forward-mode through command, the VE interface switches to the high-performance forwarding mode, and the total bandwidth of the VE interfaces equals the total bandwidth of the interface board.

Precautions

This command can be run only on an L2VE main interface.

This command is supported only on the admin VS.