ORA-3136 in 10.2

Mon Jun 4 01:59:08 2007
WARNING: inbound connection timed out (ORA-3136)

> oerr ora 3136
03136, 00000, "inbound connection timed out"
// *Cause: Inbound connection was timed out by the server because
// user authentication was not completed within the given time
// specified by SQLNET.INBOUND_CONNECT_TIMEOUT or its default value
// *Action: 1) Check SQL*NET and RDBMS log for trace of suspicious connections.
// 2) Configure SQL*NET with a proper inbound connect timeout value
// if necessary.

The log in sqlnet.log is

***********************************************************************
Fatal NI connect error 12170.

VERSION INFORMATION:
TNS for HPUX: Version 10.2.0.2.0 - Production
Oracle Bequeath NT Protocol Adapter for HPUX: Version 10.2.0.2.0 - Production
TCP/IP NT Protocol Adapter for HPUX: Version 10.2.0.2.0 - Production
Time: 04-JUN-2007 01:59:08
Tracing not turned on.
Tns error struct:
ns main err code: 12535
TNS-12535: TNS:operation timed out
ns secondary err code: 12606
nt main err code: 0
nt secondary err code: 0
nt OS err code: 0
Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=10.22.100.155)(PORT=1341))

According to metalink notes: 345197.1 and 316901.1, the default value in 10.2 is 60 seconds ( 0 second in 10.1)

Hence, we might need to monitor the frequency to decide whether need to set INBOUND_CONNECT_TIMEOUT =0


Oracle also recommends set for both listener and database.
Hence as below to listener.ora is advised.

INBOUND_CONNECT_TIMEOUT_ = 0