bfd bind peer-ipv6 source-ipv6 auto

Function

The bfd bind peer-ipv6 source-ipv6 auto command creates a BFD session for IPv6 with automatically negotiated discriminators and displays the BFD session view.

By default, no static BFD for IPv6 session with automatically negotiated discriminators is created.

Format

bfd sessname-value bind peer-ipv6 peerip6-value [ vpn-instance vpnname-value ] [ interface { interface-value | ifType ifNum } ] source-ipv6 sourceip6-value auto

Parameters

Parameter	Description	Value
sessname-value	Specifies the name of a BFD session for IPv6.	The value is a string of 1 to 64 characters, spaces not supported. When quotation marks are used around the string, spaces are allowed in the string. When configuring a BFD session name, ensure that the uppercase and lowercase letters in the name are the same as those entered by the user. The system does not distinguish between uppercase and lowercase letters when checking the name of a BFD session. For example, ABC and abc are considered as one BFD session name. If ABC has been configured, the BFD session view of ABC is directly displayed when abc is configured. The value is a string of 1 to 64 characters, spaces not supported. When quotation marks are used around the string, spaces are allowed in the string. When configuring a BFD session name, ensure that the uppercase and lowercase letters in the name are the same as those entered by the user. The system does not distinguish between uppercase and lowercase letters when checking the name of a BFD session. For example, ABC and abc are considered as one BFD session name. If ABC has been configured, the BFD session view of ABC is directly displayed when abc is configured.
peer-ipv6 peerip6-value	Specifies the peer IPv6 address bound to a BFD session for IPv6.	The value is in 32-digit hexadecimal notation.
vpn-instance vpnname-value	Specifies the name of a VPN instance bound to a BFD session for IPv6.	The value is a string of 1 to 31 case-sensitive characters, spaces not supported. In addition, the VPN instance name must not be _public_. When double quotation marks are used around the string, spaces are allowed in the string.
interface ifType ifNum	Specifies the type and number of a Layer 3 interface to which a BFD session for IPv6 is bound.	The interface is either a physical interface (such as a GE interface) or a logical interface (such as a trunk interface or a sub-interface).
interface interface-value	Specifies the local Layer 3 interface bound to a BFD for IPv6 session.	-
source-ipv6 sourceip6-value	Specifies the source IPv6 address carried in a BFD packet.	The value is in 32-digit hexadecimal notation.

Views

System view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bfd	write

Usage Guidelines

Usage Scenario

A BFD session for IPv6 is established to rapidly detect faults in IPv6 links on a network. A device needs to establish a BFD session with a remote device on which a dynamic BFD session is established to detect faults in static routes. In this case, the bfd bind peer-ipv6 source-ipv6 auto command is used to create a BFD session for IPv6 with automatically negotiated discriminators.

When creating a static BFD session for IPv6 with automatically negotiated discriminators:

If only the peer IPv6 address is specified, BFD detects faults in a multi-hop link.
If both the peer IPv6 address and local interface are specified, BFD detects faults in a single-hop link. That is, BFD monitors a fixed route whose outbound interface is this interface and the next-hop address is the peer IPv6 address.
If the source IPv6 address is specified for the interface whose physical status is to be monitored by BFD, BFD packets are correctly forwarded after URPF has been enabled. The source-ipv6 parameter must be configured correctly because the system checks only the validity of the source IPv6 address. A multicast or broadcast address is an invalid source IPv6 address.
If both the peer IPv6 address and the VPN instance are specified, BFD detects faults in the multi-hop link for a specified VPN instance.
If the peer IPv6 address, the VPN instance, and the local interface are specified, BFD detects faults in the single-hop link for a specified VPN instance.

Follow-up Procedure

After a static BFD session for IPv6 with automatically negotiated discriminators is created and the BFD session for IPv6 view is displayed:

Run the description command to configure a description for the BFD session for IPv6.
Run the min-tx-interval command to set a desired minimum interval at which BFD packets are sent.
Run the min-rx-interval command to set a desired minimum interval at which BFD packets are received.
Run the detect-multiplier command to set a local detection multiplier for the BFD session.
Run the process-pst command to enable BFD to modify the PST if BFD detects a fault.
Run the wtr command to set a WTR time for the BFD session for IPv6.

Precautions

The difference between a static BFD session for IPv6 and a static BFD session for IPv6 with automatically negotiated discriminators is as follows:
A static BFD session for IPv6 requires the configuration of local and remote discriminators.
A static BFD session for IPv6 with automatically negotiated discriminators does not require the configuration of local or remote discriminator.
If the IPv6 address of an outbound interface is changed after the BFD session for IPv6 has been configured, the IPv6 address carried in the BFD packets will not be changed.
The source and peer IPv6 address must be configured if automatic negotiation on a local discriminator is enabled. A multicast or broadcast address is an invalid IPv6 address.
The source IPv6 address must be configured if BFD for IPv6 with automatic negotiation on a local discriminator is enabled.
You can run the undo bfd session-name command to delete a specified BFD session and its binding information.

Example

# Create a static BFD for IPv6 session with the automatically negotiated discriminator atob and check the single-hop link from the local interface to the peer IP address 2001:db8:1::1.

<HUAWEI> system-view
[~HUAWEI] bfd
[*HUAWEI-bfd] quit
[*HUAWEI] interface GigabitEthernet 0/1/0
[*HUAWEI-GigabitEthernet0/1/0] ipv6 enable
[*HUAWEI-GigabitEthernet0/1/0] ipv6 address 2001:db8:1::2 127
[*HUAWEI-GigabitEthernet0/1/0] quit
[*HUAWEI] bfd atob bind peer-ipv6 2001:db8:1::1::1 interface GigabitEthernet 0/1/0 source-ipv6 2001:db8:1::2 auto