flex-algo (IS-IS view)

Function

The flex-algo command enables Flex-Algo advertisement.

The undo flex-algo command disables Flex-Algo advertisement.

By default, Flex-Algo advertisement is disabled.

Format

flex-algo flexAlgoIdentifier [ level-1 | level-1-2 | level-2 ]

undo flex-algo flexAlgoIdentifier [ level-1 | level-1-2 | level-2 ]

Parameters

Parameter	Description	Value
flexAlgoIdentifier	Specifies the flexible algorithm identifier.	The value is an integer that ranges from 128 to 255.
level-1	Enable Flexible Algorithm advertisement on level-1.	-
level-1-2	Enable Flexible Algorithm advertisement on level-1-2.	-
level-2	Enable Flexible Algorithm advertisement on level-2.	-

Views

IS-IS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
isis	write

Usage Guidelines

Usage Scenario

Originally, IGPs can use only the SPF algorithm to calculate the shortest paths to destination addresses based on link costs. As the SPF algorithm is fixed and cannot be adjusted by users, it cannot calculate the optimal paths based on diverse user requirements. For example, it cannot support traffic forwarding along the lowest-delay path or without passing through certain links.

With Flex-Algo, an IGP can automatically calculate eligible paths based on the link cost, delay, or TE constraint to flexibly meet TE requirements.

Devices must reach an agreement on the FAD to use. Devices using the same FAD form an independent topology to meet a personal requirement. To enable Flex-Algo advertisement for IS-IS, run the flex-algo command.

Example

# Enable the function of advertising Flex-Algo 128 in IS-IS process 1.

<HUAWEI> system-view
[~HUAWEI] isis 1
[~HUAWEI-isis-1] flex-algo 128 level-1-2