[INS-20802] Oracle Net Configuration Assistant failed ；Returning is Port 1521 free: false

redhat 6.2下安装64位11G，安装执行到配置监听NETCA时报错:[INS-20802]
Oracle Net Configuration Assistant failed

打开监听log，发现如下报错：

tail -100f  installActions2013-12-23_05-45-38PM.log 

INFO: Oracle Net Listener Startup:

INFO: The information provided for this listener is currently in use by other software on this computer. 
INFO:     Listener start failed.

INFO: Check the trace file for details: /u01/cfgtoollogs/netca/trace_OraDb11g_home1-1312235PM5225.log

INFO: Oracle Net Services configuration failed.  The exit code is 1

INFO: 

WARNING: 

INFO: Completed Plugin named: Oracle Net Configuration Assistant

日志中显示：Listener start failed，按提示打开日志：

tailf -100f /u01/cfgtoollListener start failed.ogs/netca/trace_OraDb11g_home1-1312235PM5225.log

oracle.net.ca.NetCA.main(NetCA.java:405)

[main] [ 2013-12-23 17:52:27.643 CST ] [ConfigureListener.isPortFree:1088]  Returning is Port 1539 free: false

[main] [ 2013-12-23 17:52:27.643 CST ] [ConfigureListener.typicalConfigure:217]  Failed to get free port. Using port 1521.

[main] [ 2013-12-23 17:52:27.655 CST ] [ConfigureListener.setListenerParam:1779]  Setting ADR_BASE_LISTENER: /u01

[main] [ 2013-12-23 17:52:27.658 CST ] [ConfigureListener.isPortFree:1010]  Checking if port 1521 is free on local machine...

[main] [ 2013-12-23 17:52:27.658 CST ] [ConfigureListener.isPortFree:1023]  InetAddress.getByName(127.0.0.1): /127.0.0.1

[main] [ 2013-12-23 17:52:27.659 CST ] [ConfigureListener.isPortFree:1025]  Local host IP address: rac1/192.168.2.41

[main] [ 2013-12-23 17:52:27.659 CST ] [ConfigureListener.isPortFree:1027]  Local host name: rac1

[main] [ 2013-12-23 17:52:27.660 CST ] [ConfigureListener.isPortFree:1039]  Creating ServerSocket on Port:1521, IP Address: rac1/192.168.2.41

[main] [ 2013-12-23 17:52:27.660 CST ] [ConfigureListener.isPortFree:1075]  java.net.PlainSocketImpl.socketBind(Native Method)

java.net.PlainSocketImpl.bind(PlainSocketImpl.java:359)

java.net.ServerSocket.bind(ServerSocket.java:319)

java.net.ServerSocket.<init>(ServerSocket.java:185)

oracle.net.ca.ConfigureListener.isPortFree(ConfigureListener.java:1041)

oracle.net.ca.ConfigureListener.startOrStopListener(ConfigureListener.java:1118)

oracle.net.ca.ConfigureListener.typicalConfigure(ConfigureListener.java:256)

oracle.net.ca.SilentConfigure.performSilentConfigure(SilentConfigure.java:185)

oracle.net.ca.InitialSetup.<init>(NetCA.java:4159)

oracle.net.ca.NetCA.main(NetCA.java:405)
[main] [ 2013-12-23 17:52:27.661 CST ] [ConfigureListener.isPortFree:1088]
 Returning is Port 1521 free: false

解决办法：

用root用登录：在/etc/hosts文件中将hostname与回环IP地址对应上就解决了。