Our secondary replica was disconnected from SQL Always-on Basic Availability Group (BAG) suddenly from a month ago. We have tried to re-attach the secondary replica back to BAG, but it fail. Below is the error message collected from both nodes for reference. We have no idea how to resolve this issue. Hope anyone could give us suggestion, thanks.
At secondary node, it shows extended events on AlwaysOn health as below:
error_number: 35201
message: A connection timeout has occurred while attempting to establish a connection to availability replica 'Node1' with id [XXX]. Either a networking or firewall issue exists, or the endpoint address provided for the replica is not the database mirroring endpoint of the host server instance.
At primary node, it shows extended events on AlwaysOn health as below:
error_number: 28047
message: Database Mirroring login attempt failed with error: 'Connection handshake failed. The certificate used by this endpoint was not found: Certificate expired. Use DBCC CHECKDB in master database to verify the metadata integrity of the endpoints. State 85.'. [CLIENT: X.X.X.X]
