ORA-12541: TNS:no listener
 *Cause: The connection request could not be completed because the listener
 is not running.
 *Action: Ensure that the supplied destination address matches one of
 the addresses used by the listener - compare the TNSNAMES.ORA entry with
 the appropriate LISTENER.ORA file (or TNSNAV.ORA if the connection is to
 go by way of an Interchange). Start the listener on the remote machine.

SID_LIST_LISTENER =
  (SID_LIST =
     (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = /home/oracle/product/10.2.0.1/db_1)
      (PROGRAM = extproc)
     )
     (SID_DESC =
      (GLOBAL_DBNAME = MODVMXLA01)
      (SID_NAME = MODVMXLA01)
      (ORACLE_HOME = /home/oracle/product/10.2.0.1/db_1)
     )
  )
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.1.1.11)(PORT = 1521))
    )
  )

MODVMXLA01 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.1.1.11)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SID = MODVMXLA01)
    )
  )
EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )
MODVMXLA =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST =192.168.1.32)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = MODVMXLA)
    )
  )

[oracle@localhost admin]$ lsnrctl status

LSNRCTL for Linux: Version 10.2.0.1.0 - Production on 12-SEP-2007 12:19:50

Copyright (c) 1991, 2005, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.2.0.1.0 - Production
Start Date                12-SEP-2007 11:59:30
Uptime                    0 days 0 hr. 20 min. 19 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /home/oracle/product/10.2.0.1/db_1/network/admin/listener.ora
Listener Log File         /home/oracle/product/10.2.0.1/db_1/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=10.1.1.11)(PORT=1521)))
Services Summary...
Service "MODVMXLA01" has 1 instance(s).
  Instance "MODVMXLA01", status UNKNOWN, has 1 handler(s) for this service...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

[oracle@localhost install]$ sqlplus vmxla_user/VMXLA@MODVMXLA

SQL*Plus: Release 10.2.0.1.0 - Production on Wed Sep 12 13:12:32 2007

Copyright (c) 1982, 2005, Oracle.  All rights reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL>

[oracle@localhost install]$ emctl status dbconsole
TZ set to US/Eastern
Oracle Enterprise Manager 10g Database Control Release 10.2.0.1.0
Copyright (c) 1996, 2005 Oracle Corporation.  All rights reserved.
http://localhost.localdomain:1158/em/console/aboutApplication
Oracle Enterprise Manager 10g is running.
------------------------------------------------------------------
Logs are generated in directory /home/oracle/product/10.2.0.1/db_1/localhost.localdomain_MODVMXLA01/sysman/log

Database Instance: MODVMXLA01
	
Enterprise Manager is not able to connect to the database instance. The state of the components are listed below.	
Page Refreshed		Sep 12, 2007 2:18:53 PM		
	
Database Instance
	
	
Host		
localhost.localdomain
Port		
1521
SID		
MODVMXLA01
Oracle Home		
/home/oracle/product/10.2.0.1/db_1
	
	
Listener
	
Status		
Unavailable
Host		
Port		
Name		
Oracle Home		
Location		
Details		
	
	
Agent Connection to Instance
Status		
Failed
Details		ORA-12541: TNS:no listener (DBD ERROR: OCIServerAttach)