title: Cannot connect to ExtProc In Oracle 11g
body: <p>We have two Oracle instances on one server (both 11g) that are using the same listener.  I am having an issue with connecting to the extproc:</p>
  
  <p>TNSNAMES.ORA</p>
  
  <pre><code>EXTPROC_CONNECTION_DATA.NATIONAL.SERVER.COM =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC11G))
      )
      (CONNECT_DATA =
        (SERVICE_NAME = PLSExtProc11g)
      )
    )
  </code></pre>
  
  <p>LISTENER.ORA</p>
  
  <pre><code>(DESCRIPTION_LIST=
      (DESCRIPTION =
         (ADDRESS_LIST=
           (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
           (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC11G))
       )
      )
    )
  
  SID_LIST_LISTENER =
    (SID_LIST =
      (SID_DESC =
        (SID_NAME = PLSExtProc11g)
        (ORACLE_HOME = /home/app/oracle/product/11.2.0/dbhome_1)
        (ENVS = "EXTPROC_DLLS=ANY")
        (PROGRAM = extproc)
      )
  </code></pre>
  
  <p>When I use TNSPING to check the connection, I get the following:</p>
  
  <p>/home/app/oracle/product/11.2.0/dbhome_1/network/admin/sqlnet.ora</p>
  
  <p>$tnsping EXTPROC_CONNECTION_DATA</p>
  
  <p>TNS Ping Utility for Linux: Version 11.2.0.1.0 - Production on 03-NOV-2011 14:03:41</p>
  
  <p>Copyright (c) 1997, 2009, Oracle.  All rights reserved.</p>
  
  <p>Used parameter files:</p>
  
  <p>Used TNSNAMES adapter to resolve the alias
  Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC11G))) (CONNECT_DATA = (SERVICE_NAME = PLSExtProc11g)))
  TNS-12541: TNS:no listener</p>
  
  <p>I am able successfully tnsping both of the databases but not the EXTPROC_CONNECTION_DATA.  </p>