mpls bfd-trigger-tunnel

Function

The mpls bfd-trigger-tunnel command configures a policy for dynamically establishing a BFD session to monitor LSPs in an LDP tunnel.

The undo mpls bfd-trigger-tunnel command deletes a policy for dynamically establishing a BFD session to monitor LSPs in an LDP tunnel.

By default, no trigger policy is configured.

Format

mpls bfd-trigger-tunnel { host | ip-prefix ip-prefix-name | fec-list list-name }

undo mpls bfd-trigger-tunnel

Parameters

Parameter	Description	Value
host	Indicates the host address-based policy for dynamically establishing a BFD session to monitor LSPs in an LDP tunnel.	-
ip-prefix ip-prefix-name	Specifies the name of an IP address prefix used to dynamically establish a BFD session to monitor an LDP tunnel.	The name is a string of 1 to 169 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.
fec-list list-name	Specifies the name of a FEC list used to dynamically establish a BFD session to monitor LSPs in an LDP tunnel.	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.

Parameter

Description

Value

host

Indicates the host address-based policy for dynamically establishing a BFD session to monitor LSPs in an LDP tunnel.

ip-prefix ip-prefix-name

Specifies the name of an IP address prefix used to dynamically establish a BFD session to monitor an LDP tunnel.

The name is a string of 1 to 169 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.

fec-list list-name

Specifies the name of a FEC list used to dynamically establish a BFD session to monitor LSPs in an LDP tunnel.

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.

Views

MPLS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mpls-ldp	write

Usage Guidelines

Usage Scenario

When LDP LSPs transmit application traffic, such as VPN, LDP FRR and upper-layer protection mechanism, such as VPN FRR or VPN equal-cost multipath (ECMP), are used to improve network reliability. If both the primary and FRR LSPs fail, BFD for LDP tunnel can be used to instruct a specific LDP upper-layer application to perform a protection switchover. After MPLS is enabled to dynamically establish BFD sessions using mpls bfd enable, run the mpls bfd-trigger-tunnel command to configure a policy for dynamically establishing a BFD session to monitor LSPs in an LDP tunnel.

Either of the following trigger policies can be used:

Host address-based policy: used when all host addresses are available to trigger the creation of BFD sessions. This is the default trigger method.
FEC list- or IP prefix list-based policy: used when only some host addresses can be used to establish BFD sessions.
If not parameter is configured in the mpls bfd-trigger-tunnel command, the host address-based policy is used by default.

Prerequisites

BFD has been globally enabled using the bfd command.

(Optional) If the FEC list-based policy is used, ensure that no outbound interface name or next-hop address is specified for a FEC node in a specified FEC list.

(Optional) Configure an IP address prefix list before using it to trigger LDP LSP establishment.

Precautions

The undo mpls bfd-trigger-tunnel command without a parameter configured deletes a host address-based policy by default.

Example

# Configure a host address-based policy to dynamically create a BFD session to monitor LSPs in an LDP tunnel.

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