In trying to establish connectivity from my workstation (actually, am seeing the same behavior on both WinXP32 and Win764 workstations) to an Oracle server, the first thing I always try is a tnsping. When I do so, this is what I get: 

```
> C:\>tnsping MYDBNAME
> 
> TNS Ping Utility for 32-bit Windows:
> Version 10.2.0.1.0 - Production on
> 25-JAN-2 011 15:03:35
> 
> Copyright (c) 1997, 2005, Oracle.  All
> rights reserved.
> 
> Message 3511 not found; No message
> file for product=NETWORK,
> facility=TNSMessage  3512 not found;
> No message file for product=NETWORK,
> facility=TNSAttempting to contact
> (DESCRIPTION = (ADDRESS_LIST =
> (ADDRESS = (PROTOCOL = TCP) (HOST =
> thisismyservername.com)(PORT = 1577)))
> (CONNECT_DATA = (SID = MYDBNAME)))
> Message 3509 not found; No message
> file for product=NETWORK, facility=TNS

```

So, as you can see, it is properly detecting my tnsnames file, and picks up the correct server address and port for the specified database, but the tnsping fails with 3511 and 3509 errors. 

The strange part is, using sqlplus or Toad, from the same workstation, I **can** connect to that very same database successfully. 

Can anyone explain what is happening here?

FWIW:

The ORACLE\_HOME system environment variable (and any other oracle environment variables) is **not** set.

Update
------

The ORACLE\_HOME environment variable does not necessarily HAVE to be set, it seems to depend per machine somehow. My particular issue was: Oracle 10g has/had a known defect in that tnsping.exe simply didn't work. There is a patch