ospf suppress-flapping peer

Function

The ospf suppress-flapping peer command configures detection parameters for OSPF neighbor relationship flapping suppression.

The undo ospf suppress-flapping peer command restores the default detection parameters.

The ospf suppress-flapping peer disable command disables OSPF neighbor relationship flapping suppression from an interface.

The undo ospf suppress-flapping peer disable command enables OSPF neighbor relationship flapping suppression on an interface.

The ospf suppress-flapping peer hold-down command configures the Hold-down mode and sets duration for this mode.

The undo ospf suppress-flapping peer hold-down command cancels the Hold-down mode.

The ospf suppress-flapping peer hold-max-cost disable command disables the Hold-max-cost mode.

The undo ospf suppress-flapping peer hold-max-cost disable command enables the Hold-max-cost mode.

By default, the detection interval of OSPF neighbor relationship flapping suppression is 60s, the suppression threshold is 10, and the interval for exiting from suppression is 120s.

By default, OSPF neighbor relationship flapping suppression is enabled on all interfaces.

By default, the Hold-down mode is disabled, and the Hold-max-cost mode is enabled.

By default, the Hold-max-cost mode is enabled.

Format

ospf suppress-flapping peer disable

ospf suppress-flapping peer hold-down interval

ospf suppress-flapping peer hold-max-cost disable

ospf suppress-flapping peer { detecting-interval detecting-interval | threshold threshold | resume-interval resume-interval } ^*

undo ospf suppress-flapping peer disable

undo ospf suppress-flapping peer hold-down [ interval ]

undo ospf suppress-flapping peer hold-max-cost disable

undo ospf suppress-flapping peer { detecting-interval detecting-interval | threshold threshold | resume-interval resume-interval } ^*

Parameters

Parameter	Description	Value
hold-down interval	Specifies the duration of the Hold-down mode.	The value is an integer ranging from 1 to 86400, in seconds.
detecting-interval detecting-interval	Specifies the detection interval of OSPF neighbor relationship flapping suppression. Each OSPF interface on which OSPF neighbor relationship flapping suppression is enabled starts a flapping counter. If the interval between two successive neighbor status changes from Full to a non-Full state is shorter than detecting-interval, a valid flapping_event is recorded, and the flapping_count increases by 1.	The value is an integer ranging from 1 to 300, in seconds. The default value is 60s.
threshold threshold	Specifies the threshold of OSPF neighbor relationship flapping suppression. When the flapping_count reaches or exceeds threshold, flapping suppression takes effect.	The value is an integer ranging from 1 to 1000. The default value is 10.
resume-interval resume-interval	Specifies the interval for exiting from OSPF neighbor relationship flapping suppression. If the interval between two successive neighbor status changes from Full to a non-Full state is longer than resume-interval, the flapping_count is reset. If OSPF neighbor relationship flapping suppression works in hold-max-cost mode, resume-interval indicates the duration of this mode. The value of. resume-interval must be greater than that of. detecting-interval.	The value is an integer ranging from 2 to 1000, in seconds. The default value is 120s.

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

To configure detection parameters for OSPF neighbor relationship flapping suppression on an interface, run the ospf suppress-flapping peer command. However, keeping the default configurations is recommended.

By default, OSPF neighbor relationship flapping suppression is enabled on all interfaces in the same OSPF process. To disable the function from one of the interfaces, run the ospf suppress-flapping peer disable command.

When an interface enters the flapping suppression state, all neighbor relationships on the interface enter the state accordingly.

Flapping suppression works in either Hold-down or Hold-max-cost mode.

Hold-down mode: In the case of frequent flooding and topology changes during neighbor relationship establishment, interfaces prevent neighbor relationship reestablishment during Hold-down suppression, which minimizes LSDB synchronization attempts and packet exchanges.
Hold-max-cost mode: If the traffic forwarding path changes frequently, interfaces use 65535 as the cost of the flapping link during Hold-max-cost suppression, which prevents traffic from passing through the flapping link.
Flapping suppression can also work first in Hold-down mode and then in Hold-max-cost mode.
By default, the Hold-max-cost mode takes effect. To configure the Hold-down mode and set duration for this mode, run the ospf suppress-flapping peer hold-down interval command.
If the hold-max-cost mode is configured for OSPF flapping suppression, you can run the ospf suppress-flapping peer resume-interval resume-interval command to set the interval for exiting from OSPF neighbor relationship flapping suppression. The resume-interval parameter value is an integer ranging from 2 to 1000, in seconds. Its default value is 120 seconds.

Prerequisites

OSPF neighbor relationship flapping suppression must have been enabled globally before you configure detection parameters for it. By default, the function is enabled. If it is disabled, run the undo suppress-flapping peer disable command to enable it before you configure the detection parameters.

OSPF neighbor relationship flapping suppression must have been enabled globally before you enable the function on an interface using the undo ospf suppress-flapping peer disable command. By default, the function is enabled globally. If it is disabled, run the undo suppress-flapping peer disable command to enable it first.

OSPF neighbor relationship flapping suppression must have been enabled globally before you configure the Hold-down mode and set duration for this mode. By default, the function is enabled. If it is disabled, run the undo suppress-flapping peer disable command to enable it before you configure the Hold-down mode and set duration for this mode.

OSPF neighbor relationship flapping suppression must have been enabled globally before you configure duration for the Hold-max-cost mode. By default, the function is enabled. If it is disabled, run the undo suppress-flapping peer disable command to enable it before you configure duration for the Hold-max-cost mode.

Precautions

The Hold-max-cost mode takes effect only unidirectionally. If a remote device does not support OSPF neighbor relationship flapping suppression, bidirectional traffic between the local and remote devices may travel along different paths.

When the OSPF neighbor relationship flaps again, the hold-max-cost timer will be restarted. If the flapping persists, the corresponding link may fail to exit from the flapping suppression state.

If hold-down is configured, flapping suppression works first in hold-down mode and then in hold-max-cost mode by default. If only the hold-down mode is required, run the ospf suppress-flapping peer hold-max-cost disable command to disable the hold-max-cost mode.

Example

# Disable OSPF neighbor relationship flapping suppression from GigabitEthernet 0/1/0.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet0/1/0
[~HUAWEI-GigabitEthernet0/1/0] ospf suppress-flapping peer disable

# Configure the Hold-down mode and set its duration to 200s on GigabitEthernet 0/1/0.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet0/1/0
[~HUAWEI-GigabitEthernet0/1/0] ospf suppress-flapping peer hold-down 200

# Disable the Hold-max-cost mode on GigabitEthernet 0/1/0.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet0/1/0
[~HUAWEI-GigabitEthernet0/1/0] ospf suppress-flapping peer hold-max-cost disable

# Set the detection interval of OSPF neighbor relationship flapping suppression to 5s, the suppression threshold to 40, and the interval for exiting from suppression to 20s on GigabitEthernet 0/1/0.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet0/1/0
[~HUAWEI-GigabitEthernet0/1/0] ospf suppress-flapping peer detecting-interval 5 threshold 40 resume-interval 20