I wanted to create a standby database from primary database(both are having different VM running Ubuntu 16.04 ). I installed oracle database in secondary and dropped the existing database using rman in secondary.I have restarted the listener and rebooted as well and started the oracle instance in secondary in nomount.Now while i am trying to connect to this secondary instance as auxiliary from rman in primary. I am receiving the error
ORA-12528: TNS:listener: all appropriate instances are blocking new connections . I have tried adding UR=A in listner.ora, but that didn't resolve the issue.

*********************************************************************************************************
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE))(CONNECT_DATA=(UR=A)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.2.0 - Production
Start Date 27-SEP-2016 02:04:40
Uptime 0 days 0 hr. 2 min. 23 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Default Service XE
Listener Parameter File /u01/app/oracle/product/11.2.0/xe/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/ORAUBUNTU/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC_FOR_XE))(CONNECT_DATA=(UR=A)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=ORAUBUNTU)(PORT=1521))(CONNECT_DATA=(UR=A)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "XE" has 1 instance(s).
Instance "XE", status BLOCKED, has 1 handler(s) for this service...
The command completed successfully
*******************************************************************************************


# listener.ora Network Configuration File:

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/11.2.0/xe)
(PROGRAM = extproc)
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
(ADDRESS = (PROTOCOL = TCP)(HOST = ORAUBUNTU)(PORT = 1521))
(CONNECT_DATA=(UR=A))
)
)
***********************************************************************************************************

# tnsnames.ora Network Configuration File:

XE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = ubuntu)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = XE)
)
)

EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
*******************************************************************************************************

initXE.ora


db_name='XE'
*******************************************************************************************************

...
(sid_list=
   (sid_desc=
   (oracle-home=/u01/app/...)
   (sid_name=mysid)))