That's configurable and depends on your VPN use. If you just want to reach some internal corporate network ranges and have everything else go directly to the in

That's configurable and depends on your VPN use. If you just want to reach some internal corporate network ranges and have everything else go directly to the internet that's perfectly fine. If you're using a VPN for privacy reasons you have to set it up properly of course. On linux network namespaces can help with that where you can make sure that default namespace goes through your VPN and your ethernet device gets moved to a separate namespace that applications don't even see by default.