Oracle SQL Developer：测试失败：网络适配器无法建立连接？

我这里真的需要帮助。我在 VirtualBox VM 上设置了 Oracle 数据库服务器，直到昨天一切似乎都工作正常。今天，当我启动数据库继续工作，并在本地计算机（客户端计算机）中打开 SQLDeveloper 时，它向我抛出了以下错误：

Erro de ES: The Network Adapter could not establish the connection

我的 VirtualBox VM 网络设置配置为bridged adapter。我能够正常连接，今天，这个错误突然开始发生。

我做了一些研究，但没有一个对我有用。尝试遵循这个人的解决方案：Oracle SQL Developer：失败 - 测试失败：网络适配器无法建立连接？并且效果不佳。我要分享我的lsnrctl status我的文件在这里，你可以看一下。

首先，这是我开始设置的方式：

1. lsnrctl start启动监听器。导致：

LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 24-AUG-2020 10:40:56

Copyright (c) 1991, 2016, Oracle.  All rights reserved.

Starting /u01/app/oracle/product/12.2.0/dbhome_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 12.2.0.1.0 - Production
System parameter file is /u01/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/diag/tnslsnr/dbserver/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=dbserver)(PORT=1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=dbserver)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 12.2.0.1.0 - Production
Start Date                24-AUG-2020 10:40:56
Uptime                    0 days 0 hr. 0 min. 0 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora
Listener Log File         /u01/app/oracle/diag/tnslsnr/dbserver/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=dbserver)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
The listener supports no services
The command completed successfully

2. sqlplus / as sysdba启动 sqlplus shell 然后startup启动数据库实例，这给出：

ORACLE instance started.

Total System Global Area 2550136832 bytes
Fixed Size          8623928 bytes
Variable Size         671090888 bytes
Database Buffers     1862270976 bytes
Redo Buffers            8151040 bytes
Database mounted.
Database opened.

Then my lsnrctl status gives:

LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 24-AUG-2020 10:46:34

Copyright (c) 1991, 2016, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=dbserver)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 12.2.0.1.0 - Production
Start Date                24-AUG-2020 10:40:56
Uptime                    0 days 0 hr. 5 min. 38 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora
Listener Log File         /u01/app/oracle/diag/tnslsnr/dbserver/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=dbserver)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=dbserver)(PORT=5500))(Security=(I removed the path for security))(Presentation=HTTP)(Session=RAW))
Services Summary...
Service "orcl" has 1 instance(s).
  Instance "orcl", status READY, has 1 handler(s) for this service...
Service "orclXDB" has 1 instance(s).
  Instance "orcl", status READY, has 1 handler(s) for this service...
The command completed successfully

My listener.ora:

# listener.ora Network Configuration File: /u01/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora
# Generated by Oracle configuration tools.

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

My tnsnames.ora:

  GNU nano 2.9.8                                                                                   tnsnames.ora                                                                                   Modified  

# tnsnames.ora Network Configuration File: /u01/app/oracle/product/12.2.0/dbhome_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.

LISTENER_ORCL =
  (ADDRESS = (PROTOCOL = TCP)(HOST = dbserver)(PORT = 1521))


ORCL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = dbserver)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

当我尝试通过安装在虚拟机（即服务器端）内的 SQLDeveloper 连接数据库时，它工作正常，但是当我尝试从本地计算机（客户端）上的 SQLDeveloper 连接时，我会抛出错误。 我看到的每个帖子都告诉我查看听众状态，但我认为这不是问题。

我将不胜感激任何帮助。非常感谢您，任何其他信息我都会在这里回答。 =D

EDIT：忘记提及我正在使用 Oracle 数据库的 12c 版本

EDIT: Here is how I'm trying to connect to the DB:

EDIT： 当我ping数据库的主机我得到这个：

   [oracle@dbserver admin]$ ping dbserver
PING dbserver(dbserver (fe80::f8dd:c03c:920c:5442%enp0s3)) 56 data bytes
64 bytes from dbserver (fe80::f8dd:c03c:920c:5442%enp0s3): icmp_seq=1 ttl=64 time=0.075 ms
64 bytes from dbserver (fe80::f8dd:c03c:920c:5442%enp0s3): icmp_seq=2 ttl=64 time=0.053 ms
64 bytes from dbserver (fe80::f8dd:c03c:920c:5442%enp0s3): icmp_seq=3 ttl=64 time=0.051 ms
64 bytes from dbserver (fe80::f8dd:c03c:920c:5442%enp0s3): icmp_seq=4 ttl=64 time=0.072 ms
64 bytes from dbserver (fe80::f8dd:c03c:920c:5442%enp0s3): icmp_seq=5 ttl=64 time=0.049 ms
^C
--- dbserver ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 131ms
rtt min/avg/max/mdev = 0.049/0.060/0.075/0.011 ms

我曾经与虚拟机网络设置作斗争，以便我的主机可以“看到”我的虚拟机，反之亦然。

一旦我了解了端口转发，我就不再担心这个问题了。

您可以简单地告诉 VirtualBox 从本地端口（例如 1521）获取流量，并将其转发到虚拟机（例如 1521）。

因此，当从 SQL Developer 中的主机连接到 VM 时，我可以转到 localhost:1521，并将连接流量发送到 Linux VBox 映像上的 Oracle Listener，侦听端口 1521

点击端口转发

添加 TCP 1521 和 1521 的条目

然后，在 SQL Developer 中，您只需执行此操作即可连接到 VM 上的数据库