ORA-12154: TNS:could not resolve.....with a twist

This is common problem. You have to check two things:
1. Turn off the firewall on XP and antiviruses.

2. Try to use static registration of the 10g instance:

For STATIC registration of the Oracle service to the Listener:

Go to the remote 10g installation.
In ...\network\admin open listener.ora

see

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = D:\Ora10g)
      (PROGRAM = extproc)
    )
    (SID_DESC =
      (SID_NAME = test)
      (ORACLE_HOME = D:\Ora10g)
    )
  )

Add the entry
    (SID_DESC =
      (SID_NAME = test)
      (ORACLE_HOME = D:\Ora10g)
    )
with regard to the particular Oracle Home and SID Name.

Restart the listener:
c:>lsnrctl stop
c:>lsnctl start

Thats all.

schwertner:

1.  Not sure if firewall and antivirus is relavant. Everything is on my local machine.
2.  I tried changing and restarting the listener.ora as you said, but that didn't work. Here is how the listener.ora looked after the change:

# listener.ora Network Configuration File: D:\oracle10g\product\10.2.0\db_1\network\admin\listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = D:\oracle10g\product\10.2.0\db_1)
      (PROGRAM = extproc)
    )
  (SID_DESC =
      (SID_NAME = orcl)
      (ORACLE_HOME = D:\oracle10g\product\10.2.0\db_1)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
      (ADDRESS = (PROTOCOL = TCP)(HOST = DLV27-SCOTTSA1.northgrum.com)(PORT = 1522))
    )
  )


sathyagiri:

1.  ORACLE/ALL_HOMES /DEFAULT_HOME is OraHome92 (which is the oracle home for my 9i database)
ORACLE/ALL_HOMES /HOME_COUNTER is 1.
So maybe OraDb10g_home1 isn't being recognized....not really sure how it works.

2.  Here is the contents of the system path variable, broken out for readability...
D:\OWB_Home\bin;
D:\oracle10g\product\10.2.0\db_1\bin;
c:\oracle\ora92\bin;
C:\Program Files\Oracle\jre\1.3.1\bin;
C:\Program Files\Oracle\jre\1.1.8\bin;
%SystemRoot%\system32;
%SystemRoot%;
%SystemRoot%\System32\Wbem;
C:\Program Files\Common Files\Roxio Shared\DLLShared;
C:\Program Files\Microsoft SQL Server\80\Tools\BINN

Remember, the problem is I can login to SQLPLUS, but not TOAD and sqlldr.

Thanks guys

Because of the firewall and antiviruses.

You use the 10g ORACLE_HOME to connect to 9i database also. Configure the tnsnames.ora and listener.ora in 10g.

wscott30:

The firewall can stop transactions via ports.

Also try to make the DEFAULT_HOME the home where the tnsnames.ora you use reside.