ospfv3 bfd

Function

The ospfv3 bfd command enables the bidirectional forwarding detection (BFD) on the specified interface enabled with OSPFv3, or sets the parameter values of a BFD session.

The undo ospfv3 bfd command deletes the BFD on the specified interface, or restores the default parameter values of a BFD session.

By default, BFD is not enabled at OSPFv3 interface level.

Product	Support
S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S	Supported
S2720-EI, S5720I-SI, S5720-LI, S5735-L, S5735S-L, S5735S-L-M, S5720S-LI, S5720S-SI, S5720-SI, S5735-S, S5735S-S, S5735-S-I, S5730S-EI, S5730-SI, S6720-LI, S6720S-LI, S6720S-SI, and S6720-SI	Not supported

Format

ospfv3 bfd enable [ instance instance-id ]

ospfv3 bfd { min-transmit-interval min-transmit-value | min-receive-interval min-receive-value | detect-multiplier detect-multiplier-value } ^* [ instance instance-id ]

undo ospfv3 bfd enable [ instance instance-id ]

undo ospfv3 bfd { min-transmit-interval [ min-transmit-value ] | min-receive-interval [ min-receive-value ] | detect-multiplier [detect-multiplier-value ] } ^* [ instance instance-id ]

Parameters

Parameter	Description	Value
enable	Indicates enable BFD for OSPFv3 in the specified interface.	-
min-transmit-interval min-transmit-value	Specifies the minimum interval for sending BFD packets to the peer.	The value is an integer that ranges from 100 to 1000, in milliseconds. After the set service-mode enhanced command is configured on the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, and S6720-HI, the value ranges from 3 to 1000. After the set service-mode enhanced-bfd command is configured on the S5732-H, S6730-H, S6730S-H, S6730-S, and S6730S-S, the value ranges from 3 to 1000.
min-receive-interval min-receive-value	Specifies the minimum interval for receiving BFD packets from the peer.	The value is an integer that ranges from 100 to 1000, in milliseconds. After the set service-mode enhanced command is configured on the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, and S6720-HI, the value ranges from 3 to 1000. After the set service-mode enhanced-bfd command is configured on the S5732-H, S6730-H, S6730S-H, S6730-S, and S6730S-S, the value ranges from 3 to 1000.
detect-multiplier detect-multiplier-value	Indicates the local detection multiplier.	The value is an integer that ranges from 3 to 50. The default value is 3.
instance instance-id	Indicates the interface instance id.	The value is an integer ranges from 0 to 255.

Views

Interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

A link fault or a topology change causes devices to recalculate routes. Therefore, the convergence of routing protocols must be as fast as possible to improve network performance.

Link faults are inevitable. Therefore, quickly detecting faults and notifying routing protocols of the faults is a feasible solution to immediately rectify link faults. If BFD is associated with routing protocols, BFD can speed up the convergence of routing protocols when a link fault occurs.

After OSPFv3 establishes a BFD session, the default parameter value is used. BFD session parameters can also be modified as required.

Actual interval at which BFD packets are transmitted on the local devices = Max { configured interval min-transmit-value at which BFD packets are transmitted, configured interval min-receive-value at which BFD packets are received on the peer device }
Actual interval at which BFD packets are received on the local devices = Max { configured interval min-transmit-value at which BFD packets are transmitted on the peer device, configured interval min-receive-value at which BFD packets are received on the local device }
Actual time for detecting BFD packets = Actual interval at which BFD packets are received on the local device x Configured detection multiplier detect-multiplier-value

For example:

On the local device, the configured interval at which BFD packets are transmitted is 200 ms; the interval at which BFD packets are received is set to 300 ms; the detection multiplier is 4.
On the peer device, the configured interval at which BFD packets are transmitted is 100 ms; the interval at which BFD packets are received is 600 ms; the detection multiplier is 5.

Then:

On the local device, the actual interval at which BFD packets are transmitted is 600 ms calculated by using the formula max {200 ms, 600 ms}; the interval at which BFD packets are received is 300 ms calculated by using the formula max {100 ms, 300 ms}; the detection period is 1500 ms calculated by multiplying 300 ms by 5.
On the peer device, the actual interval at which BFD packets are transmitted is 300 ms calculated by using the formula max {100 ms, 300 ms}, the actual interval at which BFD packets are received is 600 ms calculated by using the formula max {200 ms, 600 ms}, and the detection period is 2400 ms calculated by multiplying 600 ms by 4.

Prerequisites

The set BFD session parameters take effect only when BFD is enabled on the interface.

Configuration Impact

If the global BFD is not configured, BFD on the interface can be configured but the BFD session cannot be set up. Similarly, if the parameters of a BFD session are set but the ospfv3 bfd enable command is not configured, the BFD session cannot be set up.

The priority of BFD configured on an interface is higher than what is configured in the process. If the BFD is enabled on the interface, the BFD session is set up by using the parameters of the BFD configured on the interface.

Precautions

After BFD is configured, OSPFv3 establishes BFD sessions only with neighbors.
The ospfv3 bfd enable command and the ospfv3 bfd block command are mutually exclusive.
After BFD is disabled on the interface using the undo ospfv3 bfd enable command, the configurations of the parameters of the BFD session on the interface still exist.

Example

# Enabling BFD on OSPFv3 on interface Vlanif10.

<HUAWEI> system-view

[HUAWEI] interface vlanif 10

[HUAWEI-Vlanif10] ospfv3 bfd enable instance 1

# Configure BFD parameters on OSPFv3 on interface Vlanif10.

<HUAWEI> system-view

[HUAWEI] interface vlanif 10

[HUAWEI-Vlanif10] ospfv3 bfd min-transmit-interval 100 min-receive-interval 100 detect-multiplier 3 instance 1