ORA-12668: Dedicated server: outbound protocol does not support proxies
Cause: The protocol specified to perform an externally-identified proxy connection (database link) from a dedicated server does not support proxy connections.
Action: Specify a protocol in the Oracle Net connect descriptor used for the connection that does support externally-authenticated proxy connections. NOTE: Because of a limitation in Oracle Net, the protocol used for the proxy connection must the same as that used for the connection from the client to the server.
Error Type: ORA