I'm trying to secure my home network but don't really need the complexity of a VPN so I'm trying to figure out other options. I'd like to allow my iPhone remote access to my home servers but I can't depend on the IP address because it changes quite often (due to the 3G network, etc). Can I filter incoming connections on my router (pfsense) by MAC address or does NAT change the source as it's passing through the different routers on the internet?