在ORACLE测试服务器上还原恢复了一个数据库后，启动监听服务时出现了TNS-12541， TNS-12560，TNS-00511之类的错误，具体情况如下所示：
[oracle@getlnx01 admin]$ lsnrctl status
LSNRCTL for Linux: Version 10.2.0.4.0 - Production on 09-MAR-2015 09:13:29
Copyright (c) 1991， 2007， Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=getlnx01.esqule.com)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused
[oracle@getlnx01 dbs]$ lsnrctl start
LSNRCTL for Linux: Version 10.2.0.4.0 - Production on 09-MAR-2015 09:20:46
Copyright (c) 1991， 2007， Oracle. All rights reserved.
Starting /u01/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 10.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=getlnx01.esqule.com)(PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))
TNS-12547: TNS:lost contact
TNS-12560: TNS:protocol adapter error
TNS-00517: Lost contact
Linux Error: 104: Connection reset by peer
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=getlnx01.esqule.com)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused
　　因为曾经遇到并解决过TNS-12541这类错误，立即检查/etc/hosts文件，结果发现IP地址写错了，正确的IP地址应该为192.168.7.221，而不是粗心手误写错的192.168.7.211
　　[root@getlnx01 ~]# more /etc/hosts
　　# Do not remove the following line， or various programs
　　# that require network functionality will fail.
　　127.0.0.1      getlnx01.esqule.com getlnx01
　　192.168.7.211  getlnx01.esqule.com getlnx01