Hi,
in this post, we are going to share you a case about the switch fails to set up LDP sessions after a license is loaded to a switch with dual MPUs to enable MPLS.
Involved Products and Versions
S series modular switches running V200R005C00 to V200R008C00
Fault Symptom
After a license is loaded to an LDP-enabled switch that has two MPUs to enable MPLS, the switch fails to set up LDP sessions.
Cause Analysis
After the license is loaded, the active MPU sends a backup message to the standby MPU, but the standby MPU does not respond. This problem occurs when the following conditions are met:
1. LDP is configured on a switch with dual MPUs.
2. A valid license is loaded to the switch to enable MPLS.
Troubleshooting Procedure
1. Run the reset mpls ldp all command to reset all LDP instances.
2. If the switch runs V200R005, V200R007, or V200R008, it is recommended that you install the latest patch of the corresponding version to prevent this problem from occurring again.
That's all for this case, if you have any questions, please comment below.
Thanks.