在很多系统中经常都会看到如下报错：
系统版本：oracle 11.2.0.4 RAC
操作系统：linux、aix都有类似情况：
Archived Log entry 1253 added for thread 2 sequence 653 ID 0x6ceef059 dest 1:
Tue Jun 02 13:49:31 2015




***********************************************************************


Fatal NI connect error 12170.


  VERSION INFORMATION:
        TNS for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production
        TCP/IP NT Protocol Adapter for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production
        Oracle Bequeath NT Protocol Adapter for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production
  Time: 02-JUN-2015 13:49:31
  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: 78
    nt OS err code: 0
  Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=10.75.152.104)(PORT=63236))
Tue Jun 02 20:22:20 2015




***********************************************************************


Fatal NI connect error 12170.


  VERSION INFORMATION:
        TNS for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production
        TCP/IP NT Protocol Adapter for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production
        Oracle Bequeath NT Protocol Adapter for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production
  Time: 02-JUN-2015 20:22:20
  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: 78
    nt OS err code: 0
  Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=xxxxx)(PORT=60712))
Tue Jun 02 22:00:00 2015
Setting Resource Manager plan SCHEDULER[0x32DA]:DEFAULT_MAINTENA

关于这一类的报错大多数都是有listener.ora中的一个参数引起：INBOUND_CONNECT_TIMEOUT_
该参数默认值为60，只要将该参数修改为禁用即可，修改置为0.
有多种修改方法，如下：
LSNRCTL> show inbound_connect_timeout
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=xxxxx)(PORT=1526))
LISTENER parameter "inbound_connect_timeout" set to 60
The command completed successfully


LSNRCTL> set inbound_connect_timeout 0
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=xxxxx)(PORT=1526))
LISTENER parameter "inbound_connect_timeout" set to 0
The command completed successfully


LSNRCTL> show inbound_connect_timeout
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=xxxx)(PORT=1526))
LISTENER parameter "inbound_connect_timeout" set to 0
The command completed successfully


LSNRCTL> set save_config_on_stop on    -----------设置参数永久生效
LSNRCTL> exit

方法二：
修改listener.ora文件，加入:  INBOUND_CONNECT_TIMEOUT_LISTENER_NAME=0，在rac环境下需要单独去修改刚刚监听器。