Database connectivity problem with instant client.

Question

Guys,
I've installed the Oracle instant client basic and ODBC files in my system.
But when I create a system DSN and test the connectivity my database connectivity,it fails with
ORA-12637:Packet receive failed error
My TNSNAMES reads below:
ONDSP101.DIGITALINDIASW.NET =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = namesrv1.xy.zz.com)(PORT = 1522))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = ONDSP101)
and my SQLNET as below:
AUTOMATIC_IPC = OFF
TRACE_LEVEL_CLIENT = ON
SQLNET.INBOUND_CONNECT_TIMEOUT=20
NAMES.DEFAULT_DOMAIN = na.pg.com
NAME.DEFAULT_ZONE = na.pg.com
SQLNET.CRYPTO_SEED = "kdg:9yv2$-plo*u6b2x!"
NAMES.DIRECTORY_PATH = (ONAMES,TNSNAMES)
NAMES.PREFERRED_SERVERS =
(ADDRESS_LIST =
(ADDRESS =
(COMMUNITY = TCP.xy.zz.com)
(PROTOCOL = TCP)
(Host = namesrv1.xy.zz.com)
(Port = 1522)
(ADDRESS =
(COMMUNITY = TCP.xy.zz.com)
(PROTOCOL = TCP)
(Host = namesrv2.xy.zz.com)
(Port = 1522)
I've placed my TNSNAMES and SQLNET file in the same folder having the instant client files and I've set my TNSADMIN,LD_LIBRARY_PATH and PATH environmental variable to the folder location.
Note:I'm able to connect to the database using SQLplus.
Thanks,
Bhagat

Answer 1

12637, 00000, "Packet receive failed"
// *Cause:  A process was unable to receive a packet from another process.
// Possible causes are:
// 1. The other process was terminated.
// 2. The machine on which the other process is running went down.
// 3. Some other communications error occurred.
// *Action: If the cause is not obvious, contact Oracle Customer Support.
These days I very seldom use ODBC for Oracle - most recently it was simply to get Enterprise Architect to "talk" to Oracle. I never used it for my client applications (unlike in the fast distant past), so what I know about ODBC is seriously outdated.
Even so, a few comments. :-)
Have you tried creating a user DSN, in case a system DSN somehow works different environment wise?
The above error description sounds like the original TCP connection was successful (i.e. it is not a host unknown or not reachable error). Subsequent packets seem to fails.
To confirm, run the listener on namesrv1.xy.zz.com with logging enabled and have a look at the listener.log - does it show a connection being accepted/handled from your PC when you use the ODBC DSN?
Have you tried the Oracle ODBC drivers? When getting EA connected I had problems (also with Instant Client) and Microsoft ODBC driver for Oracle. Downloaded and installed the Oracle ODBC driver and it worked just fine first time around.
PS. You should raise this topic on the Instant Client Forum instead.