TNS-12547: TNS:lost contact TNS-12560: TNS:protocol adapter error TNS-00517: Lost contact

oracle 启动监听的时候报下列错误：

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=10.15.50.100)(PORT=1521)))
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=IPC)(KEY=EXTPROC1521)))
TNS-12541: TNS:no listener
 TNS-12560: TNS:protocol adapter error
  TNS-00511: No listener
   Linux Error: 111: Connection refused

网上很多方法都尝试了 ，始终没有解决 。在查看 /etc/hosts 内容如下：

[root@bpmdev ~]# vi /etc/hosts

127.0.0.1  bpmdev localhost.localdomain localhost

10.15.50.100  bpmdev
~

改成下列内容，为题解决

~
[root@bpmdev ~]# vi /etc/hosts

127.0.0.1  localhost.localdomain localhost

10.15.50.100  bpmdev
~