load-balance ecmp stateful enable

Function

The load-balance ecmp stateful enable command enables the ECMP load balancing consistency function and set the ECMP load balancing consistency parameters.

The undo load-balance ecmp stateful enable command disables the ECMP load balancing consistency function.

By default, the ECMP load balancing consistency function is disabled.

Format

load-balance ecmp stateful enable [ min-number min-number-value max-number max-number-value accuracy accuracy-value ]

undo load-balance ecmp stateful enable

Parameters

Parameter	Description	Value
min-number min-number-value	Specifies the minimum number of interfaces for ECMP load balancing consistency check.	The value is an integer ranging from 1 to 64. The default value is 1.
max-number max-number-value	Specifies the maximum number of interfaces for ECMP load balancing consistency check.	The value is an integer ranging from 1 to 64. The default value is 64.
accuracy accuracy-value	Specifies the accuracy of ECMP load balancing.	The value is an integer ranging from 1 to 4. The default value is 1. Value 1 indicates the original number of routes for load balancing. Value 2 indicates 64 routes for load balancing. Value 3 indicates 128 routes for load balancing. Value 4 indicates 256 routes for load balancing.

Parameter

Description

Value

min-number min-number-value

Specifies the minimum number of interfaces for ECMP load balancing consistency check.

The value is an integer ranging from 1 to 64. The default value is 1.

max-number max-number-value

Specifies the maximum number of interfaces for ECMP load balancing consistency check.

The value is an integer ranging from 1 to 64. The default value is 64.

accuracy accuracy-value

Specifies the accuracy of ECMP load balancing.

The value is an integer ranging from 1 to 4. The default value is 1.

Value 1 indicates the original number of routes for load balancing. Value 2 indicates 64 routes for load balancing. Value 3 indicates 128 routes for load balancing. Value 4 indicates 256 routes for load balancing.

Views

System view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
forwarding	write

Usage Guidelines

Usage Scenario

When a switch that participates in traffic load balancing becomes faulty, the number of equal-cost routes reduces, and so all traffic needs to be load balanced again using the hash algorithm. As a result, traffic forwarding paths may change. Requests of the same user may be sent to different servers, greatly affecting the services in which sessions need to be maintained. To prevent this problem, run the load-balance ecmp stateful enable command. This command enables the ECMP load balancing consistency function so that hash calculation is performed only for traffic on the faulty link, without affecting traffic on other normal links.

Prerequisites

To use the ECMP load balancing consistency function, ensure that different destination addresses are reachable through the same or completely different equal-cost multiple paths.

Precautions

After enabling this function, do not change the configured load balancing hash algorithm, hash algorithm offset, and load balancing mode. Otherwise, this function may be unable to take effect.
This function may be unable to take effect when outbound ports of equal-cost links are intermittently disconnected.
The ECMP load balancing consistency function only takes effect only for common IPv4 traffic, but not for traffic transmitted over tunnels.
The ECMP load balancing consistency function is unable to take effect for IPv6 traffic.

Example

# Enable the ECMP load balancing consistency function, set the minimum number and maximum number of interfaces for ECMP load balancing consistency check to 1 and 20, respectively, and set the accuracy of ECMP load balancing to 2.

<HUAWEI> system-view
[~HUAWEI] load-balance ecmp stateful enable min-number 1 max-number 20 accuracy 2