flow-label hash-fields

Function

The flow-label hash-fields command configures a hash element for flow label load balancing.

The undo flow-label hash-fields command restores the default configuration.

By default, L4 is used as a flow label hash element.

Format

flow-label hash-fields { l2 | l3 | l4 }

undo flow-label hash-fields { l2 | l3 | l4 }

Parameters

Parameter	Description	Value
l2	Uses L2 as a hash element to perform load balancing based on source and destination MAC addresses. If incoming traffic's source and destination MAC addresses are evenly distributed on an interface board, use the L2 hash element. Non-Ethernet packets cannot be balanced based on MAC addresses after this parameter is configured.	-
l3	Uses L3 as a hash element to perform load balancing based on source and destination IP addresses. If incoming traffic's source and destination IP addresses are evenly distributed on an interface board, use the L3 hash element. If the L3 hash element is used, Ethernet packets without IP information are balanced using the source and destination MAC addresses.	-
l4	Uses L4 as a hash element to perform load balancing based on source and destination IP addresses and port numbers and the protocol number. If incoming traffic's source and destination IP addresses are unevenly distributed on an interface board, use the L4 hash element. If the L4 hash element is used, Ethernet packets without IP information are balanced using the source and destination MAC addresses.	-

Parameter

Description

Value

Uses L2 as a hash element to perform load balancing based on source and destination MAC addresses. If incoming traffic's source and destination MAC addresses are evenly distributed on an interface board, use the L2 hash element.

Non-Ethernet packets cannot be balanced based on MAC addresses after this parameter is configured.

Uses L3 as a hash element to perform load balancing based on source and destination IP addresses. If incoming traffic's source and destination IP addresses are evenly distributed on an interface board, use the L3 hash element.

If the L3 hash element is used, Ethernet packets without IP information are balanced using the source and destination MAC addresses.

Uses L4 as a hash element to perform load balancing based on source and destination IP addresses and port numbers and the protocol number. If incoming traffic's source and destination IP addresses are unevenly distributed on an interface board, use the L4 hash element.

If the L4 hash element is used, Ethernet packets without IP information are balanced using the source and destination MAC addresses.

Views

System view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
forwarding	write

Usage Guidelines

Usage Scenario

After the flow label function is enabled on the ingress PE, the PE by default generates flow labels based on the IP 5-tuple information, including the protocol number, source IP address, destination IP address, source port number, and destination port number. When the source and destination MAC addresses are changed and IP 5-tuple information is unchanged, a transit node receives fixed flow labels carried in packets sent by the ingress. If multiple LSPs exist between the transit node and egress, the transit node cannot balance the packets based on flow labels. To address this problem, run the flow-label

hash-fields command to configure a correct hash element.

Precautions

If the flow-label hash-fields command is configured multiple times, only the latest configuration takes effect. After the command is run, the configured hash element is used to balance traffic in flow label scenarios.

This command applies only to the Admin-VS.

Example

# Use the L3 hash element.

<HUAWEI> system-view
[~HUAWEI] flow-label hash-fields l3