"oracle.net.ns.NetException: Unknown host specified" in JBoss EAP

Issue

• Oracle driver cannot establish a connection with the Oracle database server

  ... oracle.net.ns.NetException: Unknown host specified
      at oracle.net.resolver.HostnameNamingAdapter.resolve(HostnameNamingAdapter.java:191) [ojdbc6-11.2.0.2.0.jar:11.2.0.2.0]
      at oracle.net.resolver.NameResolver.resolveName(NameResolver.java:133) [ojdbc6-11.2.0.2.0.jar:11.2.0.2.0]
      at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:404) [ojdbc6-11.2.0.2.0.jar:11.2.0.2.0]
      at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:678) [ojdbc6-11.2.0.2.0.jar:11.2.0.2.0]
      at oracle.net.ns.NSProtocol.connect(NSProtocol.java:238) [ojdbc6-11.2.0.2.0.jar:11.2.0.2.0]
      at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1054) [ojdbc6-11.2.0.2.0.jar:11.2.0.2.0]
      at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:308) [ojdbc6-11.2.0.2.0.jar:11.2.0.2.0]
      ...