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Troubleshooting MPLS TE
No TE LSA generated
Symptom
OSPF TE is configured but no TE LSAs can be generated to describe MPLS TE attributes.
Analysis
For TE LSAs to be generated, at least one OSPF neighbor must reach the FULL state.
Solution
1.
Perform the
display current-configuration
command to check that MPLS TE is configured on
involved interfaces.
2.
Perform the
debugging ospf mpls-te
command to observe whether OSPF can receive the TE LINK
establishment message.
3.
Perform the
display ospf peer
command to check that OSPF neighbors are established correctly.
Swicthback fails to occur when the main tunnel resumes
Symptom
When data is transmitted along the protection tunnel, the main tunnel becomes normal but data still
travels along the protection tunnel. In the output of the
display
mpls
te
protection
tunnel
command, the
Switch Result field has a value of Protect-tunnel and the Work-tunnel defect state field has a value of
No-defect.
Analysis
Possible reasons include:
•
The reverting mode is
non-revertive
.
•
The reverting delay period is relatively long.
•
A switching command with higher priority forces data to travel along the protection tunnel.
Solution
1.
Execute the
display
mpls
te
protection
tunnel
command. If the Mode field in the output is
Non-revertive, the configuration defines that reverting should not occur. If you expect that
protection switching will be triggered when the main tunnel recovers, you can configure the
mpls
te
protection
tunnel
command in the main tunnel interface view to set the reverting mode as
revertive
.
2.
If the Mode field is revertive and the WTR field is a non-zero value, the reverting delay timer has
expired. When the timer expires, if the main tunnel still has no defect, data will be switched back
to the main tunnel. If you hope the switchover occurs immediately when the main tunnel recovers,
you can use the
mpls
te
protection
tunnel
command to change the reverting delay time to 0.
3.
If your case is neither 1) nor 2), check the The current switch command field in the output of the
display
mpls
te
protection
tunnel
command. If its value is Force, a switching action with a higher
priority than the signal switching is configured. If you expect that signaling can trigger switchover
when the main tunnel recovers, you can use the
mpls
te
protect-switch
clear
command to clear all
configured switching actions.