ospf bfd

Function

The ospf bfd command enables BFD on an OSPF interface or sets parameter values for a BFD session.

The undo ospf bfd command deletes BFD on an OSPF interface or restores the default parameter values of a BFD session.

By default, BFD is not enabled on any OSPF interfaces.

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

Format

ospf bfd enable

undo ospf bfd enable

ospf bfd { min-rx-interval receive-interval | min-tx-interval transmit-interval | detect-multiplier multiplier-value | frr-binding } ^*

undo ospf bfd { min-rx-interval [ receive-interval ] | min-tx-interval [ transmit-interval ] | detect-multiplier [ multiplier-value ] | frr-binding } ^*

Only the 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 support the frr-binding parameter.

Parameters

Parameter	Description	Value
enable	Enables BFD.	-
min-rx-interval receive-interval	Indicates the minimum interval at which BFD packets are received from the remote end.	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-tx-interval transmit-interval	Indicates the minimum interval at which BFD packets are sent to the remote end.	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 multiplier-value	Specifies the local detection multiplier.	The value is an integer ranging from 3 to 50. By default, it is 3.
frr-binding	Binds the BFD status to the link status of an interface. That is, when the BFD status goes Down, the link status of the interface also goes Down. This enables traffic to be switched to the backup path.	-

Views

Interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

A link failure or topology change causes devices to recalculate routes. Therefore, the convergence of routing protocols must be sped up to improve network performance.

Link faults are unavoidable. Therefore, a feasible solution is required to detect faults faster and notify routing protocols of the faults immediately. If BFD is associated with routing protocols and a link fault occurs, BFD can speed up the convergence of routing protocols.

Prerequisites

The configured parameters of the BFD session are valid on an interface only when BFD is enabled on the interface.

Procedure

The receive-interval is obtained through the negotiation between the local end and peer end by comparing the values of the local min-rx-interval and the peer min-tx-interval. If the local end fails to receive a BFD packet from the peer end within an interval of receive-interval x multiplier-value, it considers that the neighbor is Down.

Configuration Impact

If global BFD is not enabled, you can enable BFD on an interface but cannot set up BFD sessions. Similarly, if only parameters of a BFD session are set but the ospf bfd enable command is not used, the BFD session cannot be set up.

BFD configured on an interface takes precedence over BFD configured in a process. If BFD is enabled on an interface, the BFD parameters on the interface are used to establish BFD sessions.

Precautions

After BFD is enabled, BFD sessions can be created only between the two ends that have set up an OSPF neighbor relationship and the relationship is in the Exstart state.
The ospf bfd enable command and the ospf bfd block command are mutually exclusive.
After BFD is disabled from an interface through the undo ospf bfd enable command, the parameters for setting up BFD sessions remain on this interface but do not take effect.

Example

# Enable BFD on VLANIF100 and set the minimum interval for receiving BFD packets to 400 ms and the local detection multiplier to 4.

<HUAWEI> system-view
[HUAWEI] interface vlanif 100

[HUAWEI-Vlanif100] ospf bfd enable

[HUAWEI-Vlanif100] ospf bfd min-rx-interval 400 detect-multiplier 4

# Enable BFD on GE0/0/1 and set the minimum interval for receiving BFD packets to 400 ms and the local detection multiplier to 4.

<HUAWEI> system-view
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] undo portswitch
[HUAWEI-GigabitEthernet0/0/1] ospf bfd enable
[HUAWEI-GigabitEthernet0/0/1] ospf bfd min-rx-interval 400 detect-multiplier 4