oracle 12c安装好了之后，本机访问没有问题，但局域网其他机器访问不了，报错说没有监听。

原因出在服务器的listener.ora这里，它只监听了localhost，没有监听它的局域网IP这个地址。

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
  )

把IP加进去就行了

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
	  (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.248)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
  )