Private networks allow you to access your guest machine by some address that is not publicly accessible from the global internet. In general, this means your machine gets an address in the private address space.
Multiple machines within the same private network (also usually with the restriction that they're backed by the same provider) can communicate with each other on private networks.
Guest operating system support. Private networks generally require configuring the network adapters on the guest machine. This process varies from OS to OS. Vagrant ships with knowledge of how to configure networks on a variety of guest operating systems, but it is possible if you're using a particularly old or new operating system that private networks won't properly configure.
The easiest way to use a private network is to allow the IP to be assigned via DHCP.
Vagrant.configure("2") do |config| config.vm.network "private_network", type: "dhcp" end
This will automatically assign an IP address from the reserved address space.
The IP address can be determined by using
vagrant ssh to SSH into the
machine and using the appropriate command line tool to find the IP,
You can also specify a static IP address for the machine. This lets you access the Vagrant managed machine using a static, known IP. The Vagrantfile for a static IP looks like this:
Vagrant.configure("2") do |config| config.vm.network "private_network", ip: "192.168.50.4" end
It is up to the users to make sure that the static IP doesn't collide with any other machines on the same network.
While you can choose any IP you'd like, you should use an IP from the reserved private address space. These IPs are guaranteed to never be publicly routable, and most routers actually block traffic from going to them from the outside world.
If you want to manually configure the network interface yourself, you
can disable Vagrant's auto-configure feature by specifying
Vagrant.configure("2") do |config| config.vm.network "private_network", ip: "192.168.50.4", auto_config: false end