Solution to Oracle TNS-12535: TNS: Operation timeout
System Environment: OEL6.5 _ x86
Database Version: Oracle 11g 11.2.0.3.0
Client environment: Windows 7 flagship edition x86_64
I. [fault symptom]
After the "Oracle Client" is installed on the Client, Run "tnsping enmoedu" through CMD to check the connection with the Oracle database server, the system has a TNS-12535: TNS: Operation timeout
Ii. [fault status]
The error feedback information in CMD is as follows:
C: \ Users \ Enmoedu> tnsping enmoedu
TNS Ping Utility for 32-bit Windows: Version 11.2.0.3.0-Production on 18-7-
22:11:39 2014
Copyright (c) 1997,201 1, Oracle. All rights reserved.
Used parameter files:
C: \ app \ Enmoedu \ product \ 11.2.0 \ client_1 \ network \ admin \ sqlnet. ora
Alias resolved using TNSNAMES Adapter
Try to connect (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP) (HOST = 172.1
6.53.131) (PORT = 1521) (CONNECT_DATA = (SERVICE_NAME = ENMOEDU )))
TNS-12535: TNS: Operation timeout
Iii. [Fault Cause]
Because the firewall is not closed or port 1521 is not opened on the Oracle database server, it is used for Oracle listener service communication.
Iv. [troubleshooting]
Disable the iptables firewall on the Oracle database server or open the port 1521. The random fault is eliminated.
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