ospf bfd

Format

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

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

Parameters

Parameter	Description	Value
min-tx-interval transmit-interval	Specifies the minimum interval at which BFD packets are sent to the neighbor.	The value is an integer ranging from 3 to 20000, in milliseconds. The default value is 10.
min-rx-interval receive-interval	Specifies the minimum interval at which BFD packets are received from the neighbor.	The value is an integer ranging from 3 to 20000, in milliseconds. The default value is 10.
detect-multiplier multiplier-value	Specifies the local detection multiplier.	The value is an integer ranging from 3 to 50. The default value is 3.
frr-binding	Associates the BFD session status with the link status on an interface.	-

Views

100GE interface view, 10GE interface view, 25GE sub-interface view, 25GE interface view, 400GE interface view, 40GE interface view, 50GE sub-interface view, 50GE interface view, Eth-Trunk interface view, FlexE interface view, GE optical interface view, GE electrical interface view, GMPLS-UNI interface view, Global VE sub-interface view, Tunnel interface view, VBDIF interface view, VE sub-interface view, VLANIF interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
ospf	write

Usage Guidelines

Usage Scenario

Either a link fault or topology change on a network will cause routes to be re-calculated within an area. As such, speeding up the convergence of a routing protocol is critical to improving the network performance.

As link faults are inevitable, rapidly detecting these faults and notifying routing protocols is an effective way to quickly mitigate them. This includes associating BFD with a routing protocol to speed up convergence of the routing protocol once a link fault occurs.

During the configuration of OSPF IP FRR, the lower layer can fast respond to the link change so that traffic can be rapidly switched to the backup link if the primary link fails. By setting frr-binding, you can associate the BFD session status with the link status of an interface (when the BFD session goes Down, the link status of the interface becomes Down) so that link faults can be rapidly detected.

Prerequisites

BFD has been enabled on the interface.

Implementation Procedure

The receive-interval is negotiated by the local and peer ends 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 * multiplier-value, the local end considers the peer end Down.

Configuration Impact

If global BFD is not enabled, you can enable BFD on an interface, but BFD sessions cannot be set up in this case. 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 for 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 Full state.
the OSPF BFD enable command and OSPF BFD block command are mutually exclusive in function, and the later configuration overwrites the previous one.
After BFD is disabled from an interface using the undo OSPF BFD enable command, the parameters for setting up BFD sessions remain on this interface but no longer take effect.

Example

# Enable BFD on GigabitEthernet 0/1/0 and specify the minimum interval at which BFD packets are received to 40 ms and the local detection multiplier to 4.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet0/1/0
[~HUAWEI-GigabitEthernet0/1/0] ospf bfd enable
[*HUAWEI-GigabitEthernet0/1/0] ospf bfd min-rx-interval 40 detect-multiplier 4