mpls te srlg path-calculation

Function

The mpls te srlg path-calculation command configures an SRLG-based path calculation mode.

The undo mpls te srlg path-calculation command deletes an SRLG-based path calculation mode.

By default, when calculating a path, CSPF does not consider an SRLG constraint or check whether or not the primary tunnel and a bypass tunnel or a hot-standby CR-LSP are in the same SRLG.

Format

mpls te srlg path-calculation { strict | preferred }

mpls te srlg path-calculation

undo mpls te srlg path-calculation

Parameters

Parameter	Description	Value
strict	Indicates that CSPF must calculate a bypass tunnel or a hot-standby CR-LSP based on the SRLG attribute. A link that a primary tunnel uses and a link that a bypass tunnel or hot-standby CR-LSP uses must be in different SRLGs.	-
preferred	Indicates that CSPF prefers the SRLG attribute when calculating a hot-standby CR-LSP for the first time. If calculation fails, CSPF no longer uses the SRLG attribute as a constraint. If no path calculation mode is specified in the mpls te srlg path-calculation command, SRLG-based path calculation is performed in preferred mode by default.	-

Parameter

Description

Value

strict

Indicates that CSPF must calculate a bypass tunnel or a hot-standby CR-LSP based on the SRLG attribute. A link that a primary tunnel uses and a link that a bypass tunnel or hot-standby CR-LSP uses must be in different SRLGs.

preferred

Indicates that CSPF prefers the SRLG attribute when calculating a hot-standby CR-LSP for the first time. If calculation fails, CSPF no longer uses the SRLG attribute as a constraint.

If no path calculation mode is specified in the mpls te srlg path-calculation command, SRLG-based path calculation is performed in preferred mode by default.

Views

MPLS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mpls-te	write

Usage Guidelines

Usage Scenario

In the TE hot standby scenario, the mpls te srlg path-calculation command on the ingress of a primary tunnel is run to enable CSPF to calculate a path for a hot-standby CR-LSP based on the SRLG attribute.

If strict is configured, CSPF uses an SRLG as a constraint when calculating a path for a hot-standby CR-LSP.

If preferred is configured, CSPF uses an SRLG as a constraint when calculating a path for a hot-standby CR-LSP for the first time; if calculation fails, CSPF no longer uses the SRLG as a constraint.

When SRLG is used, only the SRLG configured on the out-interface of corresponding main LSP is considered.

Example

# Enable SRLG-based path calculation in strict mode.

<HUAWEI> system-view
[~HUAWEI] mpls
[*HUAWEI-mpls] mpls te
[*HUAWEI-mpls] mpls te srlg path-calculation strict