title: How to configure interfaces to run a virtualised firewall on QEMU on a host with only one network interface?
body: <p>I lease a virtual machine that hosts a website and some backends for my projects. I'd like to set up a VPN endpoint, preferably on OpenWRT or Mikrotik CHR, so I thought that using a VM and 'hiding' all backends behind a NAT would be a good idea.
  Now here is the problem: how to configure VM so it would exclusively use host's network interface (with 'public' - now host's - IP address claimed by the OpenWRT VM) and have a second interface to access the host via virtualised LAN? So far I've only tried using QEMU's NAT-ed stack and confirmed that OpenWRT has an internet access through it.</p>