Do you know how to virtualize a firewall on VirtualBox's NAT network?

yzT

Just using VMs and not the host, do you know how to set a firewall that only works for the virtual network? The idea is like the host is "Internet" and the VMs are the local network.

If I wanted to use the host as the firewall, this would be pretty trivial, but I don't want to mess with my local iptables to use it on a testing environment.

All traffic should go through this VM.