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LDP_1.3.6.1.2.1.10.166.4.0.4 mplsLdpSessionDown

Description

LDP/2/SESSIONDOWN: OID [OID] The session went Down. (LdpId=[OPAQUE], LdpEntityIndex=[GAUGE], PeerLdpId=[OPAQUE], PeerLdpId=[OPAQUE], IfIndex=[INTEGER], SessionState=[INTEGER], DiscontinuityTime=[TIMETICK], UnknownMesTypeErrors=[COUNTER], UnknownTlvErrors=[COUNTER], DownReason=[INTEGER], IfName=[STRING])

The status of the LDP session was Down, and LSPs maintained by the session were deleted.

Attribute

Alarm ID Alarm Severity Alarm Type
1.3.6.1.2.1.10.166.4.0.4

Major

communicationsAlarm(2)

Parameters

Name Meaning

oid

Indicates the MIB object ID of the alarm.

LdpId

Indicates the LSR ID of the local end and Label Space.

LdpEntityIndex

Indicates the index of the LDP interface.

PeerLdpId

Indicates the LSR ID of the neighbor and Label Space. This parameter, LdpId, and LdpEntityIndex are indexes for SessionState, DiscontinuityTime, UnknownMesTypeErrors, and UnknownTlvErrors.

PeerLdpId

Indicates the LSR ID of the neighbor and Label Space. This parameter is the index for DownReason.

IfIndex

Indicates the interface index corresponding to the session.

SessionState

Indicates the session status.

DiscontinuityTime

Indicates the duration when the session is set up, in milliseconds.

UnknownMesTypeErrors

Indicates the number of unknown error messages codes.

UnknownTlvErrors

Indicates the number of unknown error TLVs codes.

DownReason

Indicates the cause that the session goes Down.

IfName

Indicates the interface name corresponding to the session.

Impact on the System

All the services based on this LDP session will be interrupted.

Possible Causes

1. Hello hold timer expired.

2. The session timer expired.

3. LDP was reset.

4. LDP was disabled.

5. MPLS was disabled.

6. The remote neighbor was deleted.

7. The GR configuration was modified.

8. The GR timer was changed.

9. The Keepalive hold timer was changed.

10. The MD5 configuration was changed.

11. The session role was changed.

12. The configuration of LDP MTU Signaling was changed.

13. The transport address was changed.

14. The LSR ID was changed.

15. A Notification message was received.

16. The transport addresses did not match.

17. The protocol entered the GR state.

18. The interface status was changed.

19. The TCP connection failed.

20. Other reasons.

Procedure

  1. Run the display mpls ldp session peer-id command to check the LDP session status. Ensure that the value of the parameter peer-id is the same as the value of the PeerLdpId field in the trap information.

    • If the value of the Status field in the command output is Operational, go to Step 2.
    • If no information is displayed or the value of the Status field in the command output is not Operational, go to Step 3.

  2. If the LDP session is already re-established, it indicates that the session may flap. In this case, services may have been interrupted. For further analysis based on the log information, go to Step 19.
  3. Run the display mpls ldp peer peer-id command to check whether there is information about the peer. Ensure that the value of the parameter peer-id is the same as the value of the PeerLdpId field in the trap information.

    • If the command output is displayed, go to Step 4.
    • If no information is displayed, check whether the IfName field in the trap information is null.
      • If so, go to Step 7.
      • If not, go to Step 13.

  4. Run the display mpls ldp session peer-id command repeatedly to check whether the LDP session flaps. Ensure that the value of the parameter peer-id is the same as the value of the PeerLdpId field in the trap information. If the Status field in the command output is sometimes displayed as Operational and sometimes displayed as Nonexistent, or no information is displayed, it indicates that the LDP session flaps.

    • If so, go to Step 5.
    • If not, go to Step 7.

  5. If the LDP session flaps, check whether the configurations are modified frequently.

    • If so, go to Step 6.
    • If not, go to Step 7.

  6. Stop modifying the configurations. Two minutes later, go to Step 18.
  7. Run the display mpls ldp peer peer-id command to check the TransportAddress field in the command output. Ensure that the value of the parameter peer-id is the same as the PeerLdpId field in the trap information. Then, run the display ip routing-table ip-address command to check whether information about the route to the peer exists. Ensure that the value of the parameter ip-address is the same as the value of the TransportAddress field in the display mpls ldp peer peer-id command output.

    • If so, go to Step 10.
    • If not, go to Step 8.

  8. Check whether the IGP route is correctly configured.

    • If OSPF is used as an IGP, run the display current-configuration configuration ospf command in the OSPF view to check whether OSPF has advertised the routes destined for the addresses of loopback interfaces and corresponding interfaces.
      • If so, go to Step 11.
      • If not, go to Step 9.
    • If IS-IS is used as an IGP, run the display this command in the loopback interface view and the corresponding interface view to check whether IS-IS is enabled.
      • If so, go to Step 11.
      • If not, go to Step 9.

  9. Restore the routing protocol configurations, and then check whether the configurations are normal according to Step 8.

    • If so, go to Step 7.
    • If not, go to Step 19.

  10. Check whether the TCP status is normal. Run the display mpls ldp peer peer-id command to check the Peer Transport Address field (remarked as S) and the Peer Discovery Source field. Ensure that the value of the parameter peer-id is the same as the value of the PeerLdpId field in the trap information. Then, run the display mpls ldp interface interface-type interface-number command to check the Transport Address field (remarked as D). Ensure that the value of the parameter interface-type interface-number is the same as the value of the Peer Discovery Source field in the display mpls ldp peer peer-id command output. Run the display tcp status command to check whether the Local Add:port field is displayed as D and whether the Foreign Add:port field is displayed as S. If the Local Add:port field is displayed as D and the Foreign Add:port field is displayed as S, it indicates that the TCP status is normal.

    • If so, go to Step 18.
    • If not, go to Step 11.

  11. Run the ping -a source-ip -c destination-address command to check whether packet loss occurs. The count value is greater than or equal to 100. Ensure that the parameter source-ip is the same as the value of the Peer Transport Address field in Step 10 and the value of the parameter destination-address is the same as the value of the Transport Address field in Step 10.

    • If packet loss occurs, go to Step 12.
    • If packet loss does not occur, go to Step 19.

  12. If the link is unstable, it indicates that the line is abnormal or there is heavy traffic on the link. Then, check the link and ensure that the link is stable, and then go to Step 18.
  13. Run the display mpls ldp interface interface-type interface-number command on both ends of the link to check the interface status. Ensure that the value of the parameter interface-type interface-number is the same as the value of the Peer Discovery Source field in Step 10.

    • If the corresponding interface exists, but the Status field is displayed as Inactive, go to Step 16.
    • If the corresponding interface does not exist, go to Step 14.

  14. Run the display this command in the interface view to check whether LDP is enabled.

    • If mpls ldp is displayed in the command output, go to Step 19.
    • If mpls ldp is not displayed in the command output, go to Step 15.

  15. Run the mpls ldp command in the interface view, and then go to Step 18.
  16. Run the display this command in the interface view to check whether the interface is shut down.

    • If shutdown is displayed in the command output, go to Step 17.
    • If shutdown is not displayed in the command output, go to Step 19.

  17. Run the undo shutdown command in the interface view, and then go to Step 18.
  18. If the trap LDP_1.3.6.1.2.1.10.166.4.0.3 mplsLdpSessionUp is displayed, it indicates that the trap LDP_1.3.6.1.2.1.10.166.4.0.4 mplsLdpSessionDown is cleared. Then, go to Step 20.
  19. Collect alarm information and configuration information, and then contact technical support personnel.
  20. End.

Related Information

None

Parent Topic: LDP
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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