I was just about to submit the exact same post - I can confirm that Docker for Mac fails in this way on my macOS 10.12 system (it is able to access the network on 10.11 as expected, of course). I guess these things are fully expected when running on a developer preview version, but maybe this feedback is useful to the developers.
@ckopper I’ve changed networks and docker is not working as expected. Was just going to update this post that the issue was my (assuming network related) but now seeing someone else with the same issue it adds some credibility to the issue. Have you noticed a difference in this behaviour from network to network. In my case I noticed this at the office and now seems to be working again on the hotel network.
Interesting! Since you mentioned it might be network-related, I tried it tethered to my phone and it worked. One of the differences seems to be that my office and home networks have IPv6 but my phone tethering is IPv4-only. I checked and I could also make it work on my original network by disabling IPv6 (or, rather, setting it to “link-local only”), so this might have something to do with it?
I guess you could try if you can make it work at your office network by trying to turn off IPv6 to see if it is the same issue. If that’s the case, this might be easy to fix for the Docker for Mac developers.
I forgot to reply here but disabling IPv6 - either by switching to link local (works of my router) or using the cmdline to turn off ipv6 or just turning it off in your router fixed then problem. Overall docker seems compatible with 10.12 - however I’ve have to completely uninstall / reinstall docked 2/3 times - so it’s stability is not consistent between startups, but I haven’t noticed docker crashing while running. I was able compile the firmware for one of my routers, which is a process that takes 2-4 hours, and had previously failed in the past (last attempt was 4-5 beta releases ago) - but using that as my metric, I was pleasantly surprised that docker worked, period