mpls te cspf multi-instance shortest-path

Function

The mpls te cspf multi-instance shortest-path command enables CSPF to calculate the shortest path using TEDB information of all IGP processes and areas.

The undo mpls te cspf multi-instance shortest-path command disables CSPF from calculating the shortest path TEDB information of all IGP processes and areas.

By default, the multi-instance shortest path policy is disabled.

Format

mpls te cspf multi-instance shortest-path [ preferred-igp { isis | ospf } [ process-id ] ]

undo mpls te cspf multi-instance shortest-path

Parameters

Parameter	Description	Value
preferred-igp	Enables CSPF to use a preferred IGP.	-
isis	Enables CSPF to use the preferred IS-IS traffic engineering database (TEDB).	-
ospf	Enables CSPF to use the preferred OSPF TEDB.	-
process-id	Specifies an IGP process ID.	The value is an integer ranging from 1 to 4294967295.

Views

MPLS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mpls-te	write

Usage Guidelines

Usage Scenario

In the IGP multi-instance scenario, without the

mpls te cspf multi-instance shortest-path command, CSPF calculates the shortest path using TEDB information in the first area. If the shortest path is successfully calculated, it is used to establish an LSP even if another shortest path exists in another area. The

mpls te cspf multi-instance shortest-path command enables CSPF to calculate the shortest path among all IGP processes and areas.

If multiple reachable paths have the same weights, CSPF calculates the shortest path using TEDB information of the preferred IGP process or area (OSPF).
If preferred-igp is used, CSPF can be configured to use TEDB information in a specified preferred IGP process or area. If no shortest path is found, CSPF uses TEDB information in another IGP process or area to calculate the shortest path.

Configuration Impact

This command is mutually exclusive with the mpls te cspf preferred-igp command.

Precautions

This command applies to P2P tunnels, not P2MP tunnels.

The disjoint algorithm in isolated LSP computation computes isolated primary and hot-standby LSPs, which may cause a failure to obtain the shortest path.

Example

# Enable CSPF to use TEDB information in IS-IS process 1 to calculate the shortest path for an LSP.

<HUAWEI> system-view
[~HUAWEI] mpls
[*HUAWEI-mpls] mpls te
[*HUAWEI-mpls] mpls te cspf
[*HUAWEI-mpls] mpls te cspf multi-instance shortest-path preferred-igp isis 1