Regarding the Vagrant image: I'm trying to use it on OSX (El Capitan) with the latest VirtualBox. When I do vagrant up, I see the following error: No base MAC

Regarding the Vagrant image: I'm trying to use it on OSX (El Capitan) with the latest VirtualBox. When I do vagrant up, I see the following error: No base MAC address was specified. This is required for the NAT networking to work properly (and hence port forwarding, SSH, etc.). Specifying this MAC address is typically up to the box and box maintainer. Please contact the relevant person to solve this issue. If I do vagrant up again, it seems to be working, but then I see a lot of: default: Warning: Remote connection disconnect. Retrying... and it eventually times out. Any ideas on how to solve this issue? Thanks!