Oracle VirtualBox is a free, open source and powerful virtualization tool. Some minor configurations tweaks are required to access guest localhost from host computer. I am running VirtualBox with Ubuntu on my MAC OS. If you are attempting to access internet from your virtual machine, but if you are getting error, then here are few steps that you can try. In my scenario, I also wanted to access guest localhost from host system . I was able to access internet from the virtual machine after these steps: Shut down virtual machine In VirtualBox, right click on the virtual machine and go to " Settings " Select " Network " tab Select " Adapter1 " Select " Enable Network Adapter " checkbox Click on " Attached to " drop down box and select " NAT " Select " Adapter2 " Select " Enable Network Adapter " checkbox Click on " Attached to " drop down box and select " Host-only Adapter "...