peer bfd enable (BGP-VPN instance IPv6 address family view) (group)

Function

The peer bfd enable command enables a device to establish a BFD session with its peer group using default detection parameter values.

The undo peer bfd enable command cancels this function.

By default, a BGP device does not establish any BFD session with its peer group.

Format

peer group-name bfd enable [ single-hop-prefer ] [ compatible ]

undo peer group-name bfd enable

Parameters

Parameter	Description	Value
group-name	Specifies the name of a peer group.	The name is a string of 1 to 47 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.
single-hop-prefer	Preferentially creates a single-hop BFD session for BGP peers.	-
compatible	Indicates the compatibility mode. If this keyword is specified, the TTL in packets sent by BFD is set to 255.	-

Parameter

Description

Value

group-name

Specifies the name of a peer group.

The name is a string of 1 to 47 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.

single-hop-prefer

Preferentially creates a single-hop BFD session for BGP peers.

compatible

Indicates the compatibility mode. If this keyword is specified, the TTL in packets sent by BFD is set to 255.

Views

BGP-VPN instance IPv6 address family view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

BGP uses BFD to quickly detect faults in links between BGP4 peers. This accelerates network convergence. The peer bfd enable command is used to configure a device to establish a BFD session with its peer group by using default detection parameter values.

Prerequisites

A BFD session can be established only when the corresponding BGP peer relationship is in the Established state.

Configuration Impact

After the peer bfd enable command is enabled, peers or peer groups can establish IPv6 BFD sessions using default parameter values. This allows fast link fault detection.

The BFD configuration of a peer takes precedence over that of the peer group to which the peer belongs. If BFD is not configured on a peer and the peer group to which the peer belongs is enabled with BFD, the peer inherits the BFD configurations from the peer group.

Precautions

Before enabling BFD on a BGP peer, enable BFD in the system view. If no BFD detection parameter is specified, the BFD session uses the default values.

If the command is run more than once, the latest configuration overrides the previous one.

Note:

The peer bfd block command and the peer bfd enable command are mutually exclusive. After the peer bfd block command is run, the BFD session is automatically deleted.

Example

# Configure BFD for the peer group.

<HUAWEI> system-view
[~HUAWEI] ip vpn-instance vpn1
[*HUAWEI-vpn-instance-vpn1] ipv6-family
[*HUAWEI-vpn-instance-vpn1-af-ipv6] route-distinguisher 100:1
[*HUAWEI-vpn-instance-vpn1-af-ipv6] quit
[*HUAWEI-vpn-instance-vpn1] quit
[*HUAWEI] bgp 100
[*HUAWEI-bgp] ipv6-family vpn-instance vpn1
[*HUAWEI-bgp-6-vpn1] group test external
[*HUAWEI-bgp-6-vpn1] peer test as-number 200
[*HUAWEI-bgp-6-vpn1] peer test bfd enable