Consider my local network infrastructure map:
I've a device with a Virtual Machine that acts as a QOS manager/firewall to filter and prioritize traffic with complex rules that my main router cannot manage.
I would know if it's possible to route all connection to ZeroShell VM only when it's up and running, otherwise keeping the main router as default route for internet.
I need it because sometime the Firewall/QOS machine can go offline/under maintenance but i need that all devices continue to have internet access without manually change IP