RMAN-04006: error from auxiliary database: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor
Issue:  Trying to clone a database using Duplicate Database from Active Database. 
rman is not able to connect from active database and gives below error:
RMAN-04006: error from auxiliary database: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor
Solution:  
1. Copy the password file from Active database and rename it to match the SID of the clone. 
2. Create a static listener in the listner.ora as shown below 
3 start the listener. 
LISTENER_EBS_2PRE =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = erpdbpreprod1-vip)(PORT = 1571)(IP = FIRST)))
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = erpdbpreprod1)(PORT = 1571)(IP = FIRST)))
    )
  )
SID_LIST_LISTENER_EBS_2PRE =
  (SID_LIST =
    (SID_DESC =
      (GLOBAL_DBNAME = EBS_2PRE)
      (ORACLE_HOME = /u03/app/oracle/product/11.2.0/dbhome_1)
      (SID_NAME = EBS_2PRE1)
    )
  )
4. Test the connection from active database and it should connect the clone database which is in nomount stage. 
connected to target database: SPROD (DBID=xxxxxxx)
connected to auxiliary database: EBS_2PRE (not mounted)