Request for assistance setting up the listener. 11.2.0.2 on 64 bit Linux,

Question

I have installed Oracle and am able to access it locally. Unfortunately, I can't access it remotely. lsnrctl status does not list the XE instance. The following are the contents of the relevant files/command outputs:
listener.ora
# 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 = Neon)(PORT = 1521))
DEFAULT_SERVICE_LISTENER = (XE)
/etc/hosts
127.0.0.1     localhost.localdomain     localhost     Neon
::1     localhost.localdomain     localhost6     localhost
lsnrctl status
LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 04-SEP-2012 12:27:21
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
STATUS of the LISTENER
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.2.0 - Production
Start Date 31-AUG-2012 16:49:12
Uptime 3 days 19 hr. 38 min. 9 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/product/11.2.0/xe/log/diag/tnslsnr/Neon/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC_FOR_XE)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
I am able to log into the database using sqlplus mkhan/password and run the following query, select * from all_users and get the following output:
SQL> select * from all_users;
USERNAME               USER_ID CREATED
XS$NULL           2147483638 28-AUG-11
MKHAN                    49 30-AUG-12
LKEDONGA               48 23-JUL-12
APEX_040000               47 28-AUG-11
APEX_PUBLIC_USER          45 28-AUG-11
FLOWS_FILES               44 28-AUG-11
HR                    43 28-AUG-11
MDSYS                    42 28-AUG-11
ANONYMOUS               35 28-AUG-11
XDB                    34 28-AUG-11
CTXSYS                    32 28-AUG-11
USERNAME               USER_ID CREATED
OUTLN                         9 28-AUG-11
SYSTEM                         5 28-AUG-11
SYS                         0 28-AUG-11
14 rows selected.
SQL>
but attempting sqlplus mkhan/password@XE or mkhan/password@Neon/XE or mkhan/password@localhost/XE results in the following:
SQL*Plus: Release 11.2.0.2.0 Production on Tue Sep 4 13:42:36 2012
Copyright (c) 1982, 2011, Oracle. All rights reserved.
ERROR:
ORA-12514: TNS:listener does not currently know of service requested in connect
descriptor
Enter user-name:
Needless to say that Apex isn't working either but I'll tackle that later. I can log into the database using user oracle in group dba using "sqlplus / as sysdba". I can shutdown the database and start it back up. So I know I installed correctly.

Answer 1

user11414072 wrote:
Thanks Ed.
On my PC, I installed the instant client 11.2. As I understand it, when I run sqlplus in a dos box as follows, I the DB server should respond and allow a connection
sqlplus mkhan/password@XE
In this case it should use the local tnsnames.ora to determine where the XE instance is, and initiate a connection.
I've also tried
sqlplus mkhan/password@Neon/XE and
sqlplus mkhan/[email protected]/XE and
sqlplus mkhan/[email protected]/XE
sqlplus mkhan/[email protected]:1521/XE
all of them give me
ORA-12170: TNS:Connect timeout occurred
AdThanksVance,the most common cause from ORA-12170 is a FireWall on or between client & DB server
what is OS name & version for both client & DB server?