检查

监听的host的主机名是否存在

/etc/hosts 查看

如果没有则添加， 前面对应服务器IP 后面为主机名

修改oracle的监听host

oracle/product/11.2.0/dbhome_1/network/admin

vimlistener.ora

# listener.ora Network Configuration File: /home/oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
# Generated by Oracle configuration tools.

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = oracledb)(PORT = 1521))#oracle为与之对应的主机名
    )
  )

ADR_BASE_LISTENER = /home/oracle/app/oracle

ps：

如果监听host = localhost 那么 监听的是本机（服务器） 其他主机根部无法链接