Oracle "TNS-12535: TNS: operation timeout"

System environment: OEL6.5_x86

Database version: Oracle 11g 11.2.0.3.0

Client environment: Windows7 flagship x861464

1. [failure phenomenon]

After "Oracle Client" is installed on the client, run "tnsping enmoedu" through CMD to detect the connection to the Oracle database server, and the TNS-12535: TNS: operation timeout occurs in the system.

2. [fault status]

The following is the error feedback in CMD:

C:\ Users\ Enmoedu > tnsping enmoedu

TNS Ping Utility for 32-bit Windows: Version 11.2.0.3.0-Production on 18-July-

2014 22:11:39

Copyright (c) 1997, 2011, Oracle. All rights reserved.

Used parameter file:

C:\ app\ Enmoedu\ product\ 11.2.0\ client_1\ network\ admin\ sqlnet.ora

Used the TNSNAMES adapter to resolve aliases

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 timed out

3. [cause of failure]

Because the firewall is not turned off or port 1521 is not open on the firewall on the Oracle database server for Oracle listener service traffic.

4. [fault handling]

Turn off the iptables Firewall on the Oracle database server or open port 1521. The random failure phenomenon is relieved.

-- END--

The colonel wielded his sword

2014.7.18