mpls bfd-trigger

Function

The mpls bfd-trigger command configures a policy for establishing a BFD session and binding the BFD session to an LSP.

The undo mpls bfd-trigger command deletes a policy for establishing a BFD session and binding the BFD session to an LSP.

By default, no policy for establishing a BFD session and binding the BFD session to an LSP is configured.

Format

mpls bfd-trigger { host [ nexthop next-hop-address | outgoing-interface { interface-name | interface-type interface-number } ] ^* | fec-list list-name } [ option-tlv ]

undo mpls bfd-trigger

Parameters

Parameter	Description	Value
host	Indicates that all host addresses are used to create LDP BFD sessions.	-
nexthop next-hop-address	Specifies the next-hop address on an LSP.	Expressed in dotted decimal notation.
outgoing-interface	Specifies the outbound interface.	-
interface-type	Specifies the type of an outbound interface.	-
interface-number	Specifies the number of an outbound interface.	-
fec-list list-name	Specifies the name of a FEC list, by which the creation of an LDP BFD session is triggered.	The value is a string of 1 to 31 characters, spaces not supported. When quotation marks are used around the string, spaces are allowed in the string.
option-tlv	Specifies that the LDP BFD session is globally enabled.	-

Views

MPLS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mpls-ldp	write

Usage Guidelines

Usage Scenario

Either of the following trigger policies can be used to establish BFD sessions and bind the BFD sessions to LSPs:

Host address trigger policy: used when all host addresses can be used to trigger the creation of BFD sessions. You can also specify a next-hop address and an outbound interface of a specific LSP to be monitored by BFD.
FEC list trigger policy: used when only some host addresses can be used to establish BFD sessions. The FEC list contains specified host addresses.
The
mpls bfd-trigger command is run on the node that initiates a BFD session.
When a globally enabled LDP BFD session is triggered in the compatibility mode, the BFD session IP header encapsulates the Option field.

Follow-up Procedure

Configure parameters used by a dynamic BFD session to monitor LDP LSPs.

Precautions

Before a FEC list policy is used to trigger dynamic BFD that monitors LDP LSPs, the fec-list command must be run to create a FEC list.

Example

# Configure the compatibility mode trigger policy in MPLS view.

<HUAWEI> system-view
[~HUAWEI] bfd
[*HUAWEI-bfd] quit
[*HUAWEI] mpls
[*HUAWEI-mpls] mpls bfd-trigger host option-tlv

# Use host routes to trigger the establishment of BFD sessions and bind the BFD sessions to LSPs.

<HUAWEI> system-view
[~HUAWEI] bfd
[*HUAWEI-bfd] quit
[*HUAWEI] mpls
[*HUAWEI-mpls] mpls bfd-trigger host