Fatal NI connect error 12170.

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Verifiquei este erro no sqlnet.log

Uso Oracle 10g em Linux SUSE

Alguem poderia informar a possível causa e soluções possíveis

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Fatal NI connect error 12170.

VERSION INFORMATION:

TNS for Linux: Version 10.2.0.4.0 - Production

Oracle Bequeath NT Protocol Adapter for Linux: Version 10.2.0.4.0 - Production

TCP/IP NT Protocol Adapter for Linux: Version 10.2.0.4.0 - Production

Time: 28-OCT-2008 18:14:26

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=192.168.4.14)(PORT=2183))