title: What is the cause of this problem "IO Error: The Network Adapter could not establish the connection" on Sql Developer?
body: <p>I make a connection for connect to the Database Server (other machine).
  Then I found "An error was encountered performing the requested operation:
  IO Error: The Network Adapter could not establish the connection
  Vendor code 17002".</p>
  
  <p>Please look the picture in URL below.</p>
  
  <p><a href="https://i.stack.imgur.com/4Gwiz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4Gwiz.png" alt="error message"></a></p>
  
  <p>I tried to make a connection but can't access but my team can access it.
  My friend used TNS connection type and I did everthing similar him but can't access. I tried to use JDBC thin for connect but can't also.</p>
  
  <p>I had the old connection which I can connect but why I can't connect the new connection.</p>