5 Replies Latest reply: Jan 28, 2013 12:15 AM by 987439 RSS

    Can not connect to server.  TNS: no listener

    886626
      I have Oracle 11g on my server and I have installed Virtual PC for Windows 7 on it. I installed InstantClient on the Virtual PC to access the database. The listener on my server is up and running. In fact I have restarted it quit a few times when trying different things.
      My tnsnames.ora looks like this:
      LISTENER_ORCL =
        (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
      
      
      ORACLR_CONNECTION_DATA =
        (DESCRIPTION =
          (ADDRESS_LIST =
            (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
          )
          (CONNECT_DATA =
            (SID = CLRExtProc)
            (PRESENTATION = RO)
          )
        )
      
      ORCL =
        (DESCRIPTION =
          (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
          (CONNECT_DATA =
            (SERVER = DEDICATED)
            (SERVICE_NAME = orcl.0.0.68)
          )
        )
      and my listener.ora
      SID_LIST_LISTENER =
        (SID_LIST =
          (SID_DESC =
            (SID_NAME = CLRExtProc)
            (ORACLE_HOME = C:\app\bgLAB\product\11.2.0\dbhome_2)
            (PROGRAM = extproc)
            (ENVS = "EXTPROC_DLLS=ONLY:C:\app\bgLAB\product\11.2.0\dbhome_2\bin\oraclr11.dll")
          )
        )
      
      LISTENER =
        (DESCRIPTION_LIST =
          (DESCRIPTION =
            (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
            (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
          )
        )
      
      ADR_BASE_LISTENER = C:\app\bgLAB
      I'm trying to connect using scott/****@localhost:1521 and it gives the no listener error.
      Since Instant Client does not have tnsping or other utilities, I don't know how to figure this out! Please help!
        • 1. Re: Can not connect to server.  TNS: no listener
          orafad
          It does not seem this thread belongs in the Instant Client forum, with a issue not specific to IC in any way.
          niki wrote:
          (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
          That listener will only accept local connections. If you "sit" on the host itself, you should be able to connect via listner, but not from another machine.

          Try renaming listener.ora.
          Stop listener, move file to say listener.ora_moved, start listener.
          Look at lsnrctl stat output in the endpoints section.

          I'm trying to connect using scott/****@localhost:1521 and it gives the no listener error.
          As localhost means "myself", it points to loopback interface/network, is the connection string correct?

          After changing the listener per above, to listen on all interfaces, try scott@'server hostname:1521/service_name'.
          • 2. Re: Can not connect to server.  TNS: no listener
            886626
            Thanks for your reply. I was thinking about putting this in another forum if no one replies! :)
            I changed the localhost to another name, but it wasn't being recognized at all when trying to start the listener. I even tried the IP address of the client, same error:
            Connect failed because target host or object does not exist!!
            • 3. Re: Can not connect to server.  TNS: no listener
              LaurenzAlbe
              niki wrote:
              I changed the localhost to another name, but it wasn't being recognized at all when trying to start the listener. I even tried the IP address of the client, same error:
              No, you got that all backwards.
              listener.conf is on the database server, and you'll have to specify the server's address, not the client's.
              It specifies on which interface the server should listen.

              Yours,
              Laurenz Albe
              • 4. Re: Can not connect to server.  TNS: no listener
                886626
                Thanks guys. I finally got connected. In case someone else is confused like me, I connected with:
                scott/****@<name_of pc>:1521/orcl.0.0.68 when I put the <nameof_pc> in place of localhost inside my listener.ora.
                • 5. Re: Can not connect to server.  TNS: no listener
                  987439
                  Your configuration is very bad!