I am trying to make a JDBC connection from a VirtualBox Ubuntu Guest OS to an Oracle XE database running o Host. However, the connection is refused. Here are the details of my environment: VirtualBox: 4.1.4 Host OS: Windows 7 Guest OS: Ubuntu server 11.4 Networking mode: Bridged network Oracle XE database running on Host Issue: WebLogic server runs on the Ubuntu virtualbox. It attempts to connect to an Oracle XE database running on the Host OS (windows 7) with listening port 1521. On the Guest OS (Ubuntu), I am able to ping the Host computer from the Guest OS. However, when I configured a JDBC data source on the WebLogic server on the Guest OS to connect to the Oracle XE, connection took a long time, and eventually I received an "IO Exception: The Network Adapter could not establish the connection". When I tried "telnet host-ip 1521", no connection was established. With Bridge networking, I can make bi-directional connections between the host and the guest OS (e.g. connection through ssh and ftp). Is there anything I missed in the setup of Bridge networking and the guest/host OS? Note that I was able to make the same connection within a normal networking environment (i.e. not using virtual box). I am not sure whether Bridge networking is a good option for the work described above. Should I use host-only networking mode? If so, any specific configurations I need to perform? I read through the Virtual box document on setting up the host-only network, however, it lacks of details. I followed the procedures described in the manual, and couldn't even connect to the host. Could some experts here enlighten me on this issue? Much appreciated. Licheng