No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search


To have a better experience, please upgrade your IE browser.


Configuration Guide - Interface Management

CloudEngine 12800 and 12800E V200R003C00

This document describes the interface management configuration, including basic interface configuration, Ethernet interface configuration, and logical interface configuration.

Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Configuring an Interface to Transit to the Error-Down State When a Link Flapping Occurs

Configuring an Interface to Transit to the Error-Down State When a Link Flapping Occurs


The device records the status of an interface as Error-Down when it detects that a fault occurs. The interface in Error-Down state cannot receive or send packets and the interface indicator is off. Link flapping is one of the reasons that cause an interface to transit to the Error-Down state. You can configure link flapping protection to enable the device to shut down interfaces with frequent UP/Down transitions. This function prevents frequent network topology changes from affecting services. For example, two links work in primary/backup mode. If the interface of the primary link experiences frequent Up/Down transitions, services are switched between the primary and backup links. Frequent service switchovers increase load of the device and may result in service data loss. To solve this problem, you can configure link flapping protection on the interface of the primary link to prevent frequent topology changes. When the system detects frequent physical status changes on the interface of the primary link, the system directly disables the interface to trigger a primary/backup link switchover. The backup link then steadily transmits services. The link flapping protection function involves the following parameters:
  • Number of link flappings: One link flapping refers to one interface Up/Down transition.
  • Link flapping period: It is a period during which the system counts the number of link flappings.
If the number of link flappings on an interface reaches the threshold within a link flapping period, the system disables the interface and records its status as ERROR DOWN(link-flap). By default, after link flapping protection is enabled, an interface goes Error-Down if its status changes five times within 10 seconds.


  1. Run system-view

    The system view is displayed.

  2. Run port link-flap trigger error-down

    Link flapping protection is enabled on the interface.

    By default, link flapping protection is enabled on an interface.

  3. Run interface interface-type interface-number

    The interface view is displayed.

  4. (Optional) Run port link-flap { interval interval-value threshold threshold-value | interval interval-value | threshold threshold-value }

    The number of link flappings and the link flapping period are configured for the interface.

    By default, the number of link flappings is 5 and the link flapping period is 10 seconds for an interface.

  5. Run commit

    The configuration is committed.

Verifying the Configuration

Run the display error-down recovery [ interface interface-type interface-number ] command in any view to check information about the interfaces in Error-Down state.

Follow-up Procedure

When interfaces are in Error-Down state, you are advised to first check whether the optical modules and fiber on the two ends are securely installed on the optical interfaces or fail and whether the network cables on the two ends are firmly connected to the electrical interfaces.

An interface in Error-Down state can be recovered using either of the following methods:
  • Manual recovery (after an Error-Down event occurs):

    If a few interfaces need to be recovered, run the shutdown and undo shutdown commands in the interface view. Alternatively, run the restart command in the interface view to restart the interfaces, or remove and reinstall the transmission media on the optical interfaces.

  • Automatic recovery (before an Error-Down event occurs):

    If a large number of interfaces need to be recovered, manual recovery is time consuming and some interfaces may be omitted. To avoid this problem, you can run the error-down auto-recovery cause link-flap interval command in the system view to enable automatic interface recovery and set the recovery delay time. You can run the display error-down recovery command to view information about automatic interface recovery.


    This method does not take effect on interfaces that are already in Error-Down state. It takes effect only on interfaces that enter the Error-Down state after this configuration is complete.

Updated: 2019-05-05

Document ID: EDOC1100004195

Views: 18875

Downloads: 37

Average rating:
This Document Applies to these Products

Related Version

Related Documents

Previous Next