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

Reminder

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

upgrade

AR Router Troubleshooting Guide

This Product Documentation provides guidance for maintaining AR Enterprise Router, covering common information collection and fault diagnostic commands, typical fault troubleshooting guide, and troubleshooting.
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).
LDP Session Goes Down

LDP Session Goes Down

Common Causes

This fault is commonly caused by one of the following:

  • The interface on which the LDP session is established is shut down.

  • The undo mpls, undo mpls ldp, or undo mpls ldp remote peer command is run.

  • No route exists.

  • An LDP Keepalive timer expires.

  • An LDP Hello-hold timer expires.

Troubleshooting Flowchart

After an LDP session is configured, the LDP session goes Down.

The troubleshooting roadmap is as follows:
  • Check that the interface on which the LDP session is established is shut down.

  • Check that the undo mpls, undo mpls ldp, or undo mpls ldp remote peer is run.

  • Check that the routes exist.

  • Check that an LDP Hello-hold timer expires.

  • Check that an LDP Keepalive-hold timer expires.

Figure 24-2 shows the troubleshooting flowchart.

Figure 24-2  Troubleshooting flowchart for the fault that an LDP session goes Down

Troubleshooting Procedure

Context

NOTE:

Saving the results of each troubleshooting step is recommended. If your troubleshooting fails to correct the fault, you will have a record of your actions to provide Huawei technical support personnel.

Procedure

  1. Check that the interface on which the LDP session is established is shut down.

    Run the display this command in the interface view. If the following information is displayed, the interface has been shut down.

    shutdown

    • If the interface has been shut down, run the undo shutdown command to restart the interface.

    • If the interface is Up, go to Step 2.

  2. Check that the undo mpls, undo mpls ldp, or undo mpls ldp remote peer command is run.

    Run the display current-configuration command.

    • If the command output does not include the following information, MPLS is disabled.
      mpls
      
    • If the command output does not include the following information, MPLS LDP is disabled.
      mpls ldp
      
    • If the command output does not include the following information, the remote LDP session is deleted.
      mpls ldp remote peer
      

    • If an MPLS-associated configuration is deleted, re-perform the configuration.

    • If no MPLS-associated configuration is performed, go to Step 3.

  3. Check that the routes to the peer are reachable.

    Run the display ip routing-table command to view the Destination/Mask field and a route to the peer. If no route to the peer is displayed, a TCP connection cannot be established. If the route to the peer is displayed, run the ping host command. If the ping succeeds, the route is reachable. If the ping fails, the route is unreachable.

    • If no route to the peer is displayed, see OSPF Troubleshooting or IS-IS Troubleshooting to troubleshoot the problem.

    • If the route to the peer is displayed but is unreachable, see The Ping Operation Fails.

    • If the route to the peer is displayed and is reachable, go to Step 4.

  4. Check that an LDP Hello-hold timer expires.

    Run the display mpls ldp interface command. Check whether both ends of the LDP session can send Hello messages. It is recommended that the display mpls ldp interface command be run at 3second intervals. If the statistics do not change several times, the transmission of Hello messages is not functioning correctly and the Hello-hold timer expires.

    • If the Hello-hold timer expires, see The CPU Usage Is High.

    • If the Hello-hold timer does not expire, go to Step 5.

  5. Check that an LDP Keepalive-hold timer expires.

    Run the display mpls ldp session command to check whether Keepalive messages can be sent on both ends of the LDP session at 5-second intervals. If the statistics do not change several times, the transmission of Keepalive messages is not functioning correctly and the Keepalive-hold timer expires.

    • If the Keepalive-hold timer expires, see The Ping Operation Fails.

    • If the Keepalive-hold timer does not expire, go to Step 6.

  6. Collect the following information, and contact technical support personnel.

    • Results of the preceding troubleshooting procedure
    • Configuration files, logs, and alarms

Translation
Download
Updated: 2019-05-10

Document ID: EDOC1000079719

Views: 456296

Downloads: 4321

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Share
Previous Next