title: Oracle SQL Developer: Test failed: The Network Adapter could not establish the connection?
body: <p>I'm in real need of a help here. I setup a Oracle Database server on a VirtualBox VM and until yesterday everything seemed to work just fine. Today when I initiated the database to keep working, and turned on SQLDeveloper in my local machine (Client machine) it threw me this error:</p>
  <pre><code>Erro de ES: The Network Adapter could not establish the connection
  </code></pre>
  <p>My VirtualBox VM network setting is configure to <code>bridged adapter</code>. And I was able to connect just fine and today, out of nothing this error started occurring.</p>
  <p>I did some research but none of them worked for me. Tried to follow this guy solution:
  <a href="https://stackoverflow.com/questions/24127839/oracle-sql-developer-failure-test-failed-the-network-adapter-could-not-estab">Oracle SQL Developer: Failure - Test failed: The Network Adapter could not establish the connection?</a>
  And didn't work as well. I'm gonna share my <code>lsnrctl status</code> and my file here so you can take a look.</p>
  <p>First this is how I start my setup:</p>
  <p><strong>1. <code>lsnrctl start</code> to start the listener. Resulting in:</strong></p>
  <pre class="lang-none prettyprint-override"><code>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
  </code></pre>
  <p><strong>2. <code>sqlplus / as sysdba</code> to start sqlplus shell and then <code>startup</code> to start the database instance, which gives:</strong></p>
  <pre class="lang-none prettyprint-override"><code>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.
  </code></pre>
  <p><strong>Then my <code>lsnrctl status</code> gives:</strong></p>
  <pre class="lang-none prettyprint-override"><code>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 &quot;orcl&quot; has 1 instance(s).
    Instance &quot;orcl&quot;, status READY, has 1 handler(s) for this service...
  Service &quot;orclXDB&quot; has 1 instance(s).
    Instance &quot;orcl&quot;, status READY, has 1 handler(s) for this service...
  The command completed successfully
  </code></pre>
  <p>My <code>listener.ora</code>:</p>
  <pre class="lang-none prettyprint-override"><code># 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))
      )
    )
  
  </code></pre>
  <p>My <code>tnsnames.ora</code>:</p>
  <pre class="lang-none prettyprint-override"><code>  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)
      )
    )
  
  
  </code></pre>
  <p>When I try to connect in the database through the SQLDeveloper installed inside the Virtual Machine (That is the server side) it works ok, but when I try to connect from the SQLDeveloper on the local machine (Client side) i throws the error.
  Every post I saw, told me to look on the listener status, but that is not the problem, I think.</p>
  <p>I'd appreciate any help guys. And thank you very much, any additional information I`m here to answer. =D</p>
  <p><strong>EDIT</strong>: forgot to mention that I'm using version 12c of the Oracle Databse</p>
  <p><strong>EDIT</strong>: Here is how I'm trying to connect to the DB:
  <a href="https://i.stack.imgur.com/IcCyV.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IcCyV.png" alt="enter image description here" /></a></p>
  <p><strong>EDIT</strong>: When I <code>ping</code> the host for the DB I get this:</p>
  <pre class="lang-none prettyprint-override"><code>   [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
  </code></pre>