Symptom
PCEP session closed after received PCUpdate or PCInitiate message from 3rd party PCE
Conditions
All of conditions bellow:
- SR-PCC enabled (any config under "segment-routing traffic-eng pcc")
- at least one PCEP session established ("show segment-routing traffic-eng pcc ipv4 peer")
- PCE from other vendor used, which can support batching of multiple requests into single PCUpdate or PCinitiate message
Workaround
Hitting issue will result in flap of PCEP session, but PCEP session should be re-opened by PCC automatically (multiple retries with backoff timer - 1 second, 2 seconds,..)
Further Problem Description
SR-PCC was using too restrictive check for size of message, which is acceptable if PCEP message is just for request for single LSP. If PCE does support batching of multiple requests/LSPs into single PCEP message, then size of message can be higher than expected limit and PCC may close PCEP session. PCC would reject such message with "Reception of a malformed PCEP message" reason in "CLOSE Object Reason Field".
PCEP session will be re-opened automatically (if PCE is not blocking it for any reason).
