I live in an apartment complex with a great fast fiber connection to internet. The central router provides all connected apartment/computers with ip-addresses in the 10.x.x.x / 255.255.0.0 series. The gateway is 10.0.0.1.
Now, my problem is that means my neighbors computers are accessible from mine and vice versa (for example - I can control all Sonos in the neighborhood :) I can of course add another nat and have my own protected net, but there are problems with such setup.
I have a dd-wrt router and should be able to configure it to route and firewall in a proper way - but I can't figure out what setup to use? Only firewall? Set up and route from another subnet? Accept double nat?