Public networks are less private than private networks, and the exact meaning actually varies from provider to provider, hence the ambiguous definition. The idea is that while private networks should never allow the general public access to your machine, public networks can.
Confused? We kind of are, too. It is likely that public networks will be replaced by
:bridged in a future release, since that is in general what should be done with public networks, and providers that don't support bridging generally don't have any other features that map to public networks either.
The easiest way to use a public network is to allow the IP to be assigned via DHCP. In this case, defining a public network is trivially easy:
Vagrant.configure("2") do |config| config.vm.network "public_network" end
When DHCP is used, the IP can be determined by using
vagrant ssh to SSH into the machine and using the appropriate command line tool to find the IP, such as
Default Network Interface
If more than one network interface is available on the host machine, Vagrant will ask you to choose which interface the virtual machine should bridge to. A default interface can be specified by adding a
:bridge clause to the network definition.
config.vm.network "public_network", :bridge => 'en1: Wi-Fi (AirPort)'
The string identifying the desired interface must exactly match the name of an available interface. If it can't be found, Vagrant will ask you to pick from a list of available network interfaces.