I would like to simulate different network setups, mainly a symmetric NAT using OpenWRT in VirtualBox. I have installed OpenWRT following this and this and a couple of VMs that use the virtual router. This seems to work fine.
Now I'd like to change the OpenWRT setup to act as a symmetric NAT. How can I do this? So far I have found this, which uses iptables to achieve the goal. Is this doable also with OpenWRT?