To avoid conflicts, InternetSharing takes it upon itself to modify the subnet by one octet (172.20.0.1 -> 172.20.1.1) which is the opposite of what I want.

Apple says that you can change the subnet by modifying SharingNumberStart in the nat defaults file but this won't work if you already have any device assigned to an IP in that subnet. My own DNS, my own DHCP server and I want to pick my own damn subnet. It looked a little too complex.įirst, the reason(s) why I didn't want to use Apple's InternetSharing app even though while using it, the VMs on both MacBooks could ping one another and the Internet. One thing I didn't get into was pf, though. I typed in netstat -nr|more and ifconfig more times than I can count. I experimented with VLANs, bridges, routing tables, Parallels NAT, Apple NAT, InternetSharing, ipfw, config files and other stuff I've forgotten. While attempting to figure out how to setup a virtual network for two MacBooks connected to one another over Ethernet, I found a few helpful resources, but none helped me understand exactly how OS X does natd within InternetSharing and no matter whose blog or tutorial I followed, I just couldn't get /usr/sbin/natd to forward my packets. Apparently, nat would just stop working for some folks after they upgraded to Lion from Snow Leopard.įinding really in-depth information about Apple's NAT implementation is surprisingly hard. It appears Apple changed the way NAT works, starting in Lion and this upset a lot of people.

Parallels 6 mac os x mountain lion