About Fatal NI connect error 12170

The error in sqlnet. log is as follows:

Fatal Ni connect error 12170.

Version Information:
TNS for Linux: Version 10.2.0.1.0-Production
Oracle bequeath nt protocol adapter for Linux: Version 10.2.0.1.0-Production
TCP/IP nt protocol adapter for Linux: Version 10.2.0.1.0-Production
Time: 29-nov-2006 19:13:40
Tracing not turned on.
TNS error struct:
NS main err code: 12535
TNS-12535: TNS: Operation timed out
NS secondary err code: 12560
NT main err code: 505
TNS-00505: Operation timed out.
NT secondary err code: 110
Nt OS err code: 0
Client address: (ADDRESS = (PROTOCOL = tcp) (HOST = 219.239.13.3) (PORT = 19948 ))

# Object Storage Service (oerr) tns 12170
12170,000 00, "TNS: Connect timeout occurred"
// * Cause: The server shut down because connection establishment or
// Communication with a client failed to complete within the allotted time
// Interval. This may be a result of network or system delays; or this may
// Indicate that a malicious client is trying to cause a Denial of Service
// Attack on the server.
// * Action: If the error occurred because of a slow network or system,
// Reconfigure one or all of the parameters SQLNET. INBOUND_CONNECT_TIMEOUT,
// SQLNET. SEND_TIMEOUT, SQLNET. RECV_TIMEOUT in sqlnet. ora to larger values.
// If a malicious client is suspected, use the address in sqlnet. log
// Identify the source and restrict access. Note that logged addresses may
// Not be reliable as they can be forged (e.g. in TCP/IP ).

Increase the parameters in sqlnet. ora:
SQLNET. INBOUND_CONNECT_TIMEOUT = 30
SQLNET. RECV_TIMEOUT = 30
SQLNET. SEND_TIMEOUT = 30

Add the following in listener. ora:
INBOUND_CONNECT_TIMEOUT_LISTENER = 30

Restart listener:
Lsnrctl reload

 

Let's see how it works.