Proposal mismatch
Symptom
The proposals mismatch.
Analysis
The following is the debugging information:
got NOTIFY of type NO_PROPOSAL_CHOSEN
Or
drop message from A.B.C.D due to notification type NO_PROPOSAL_CHOSEN
The two parties in the negotiation have no matched proposals.
Solution
For the negotiation in phase 1, check that IKE proposals on both ends have a match. For the negotiation in phase 2, check that the IPsec policy settings match on both ends, and that the referenced IPsec transform sets on both ends have a match in protocol, encryption and authentication algorithms.