@lanodan @novenary @tetra
Also, the primary reason preventing those outside from sending unsolicited packets to hosts behind the NAT is that routers outside don't know where to route the private IPs that are used behind the NAT.
But if you sit on the same network segment as the NAT box's WAN port, you can send a packet directly to it with private IP as a destination, and it will forward that into the LAN.
Unless it also has a firewall (it should)