title: Cannot access oracle using sqlplus from another machine on the LAN
body: <p>I have Oracle running on one machine of the LAN.<br>
  I can connect to the DB with sqlplus when I issue:  </p>
  
  <pre><code>sqlplus myuser/mypass@localhost:1521/orcl
  </code></pre>
  
  <p>This works fine.  </p>
  
  <p>On another machine from the LAN, I have installed oracle instant client (basic + sdk + sqlplus).</p>
  
  <pre><code>sqlplus myuser/mypass@oracle_server:1521/orcl
  SQL*Plus: Release 11.2.0.3.0 Production on Sat Feb 25 09:10:41 2012
  
  Copyright (c) 1982, 2011, Oracle.  All rights reserved.
  
  ERROR:
  ORA-12543: TNS:destination host unreachable
  
  Enter user-name: 
  </code></pre>
  
  <p>Oracle server is up and running and is reachable on the network but I cannot connect to the database.</p>