Vagrant times out waiting for machine to boot (Virtualbox) - vagrant

Question

To preface, I realize this is a common error message with several different causes and solutions, but nothing I've found has worked so far. I have Vagrant 2.1.5 with Virtualbox 5.2.18, running on Windows 10.
I was testing Vagrant with a very simple Vagrantfile:
Vagrant.configure("2") do |config|
config.vm.box = "centos/7"
end
Running vagrant up then gives the typical "Timed out while waiting for the machine to boot" error:
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Importing base box 'centos/7'...
==> default: Matching MAC address for NAT networking...
==> default: Checking if box 'centos/7' is up to date...
==> default: Setting the name of the VM: vargrantTest_default_1537805339381_15444
==> default: Clearing any previously set network interfaces...
==> default: Preparing network interfaces based on configuration...
default: Adapter 1: nat
==> default: Forwarding ports...
default: 22 (guest) => 2222 (host) (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
default: SSH address: 127.0.0.1:2222
default: SSH username: vagrant
default: SSH auth method: private key
Timed out while waiting for the machine to boot. This means that
Vagrant was unable to communicate with the guest machine within
the configured ("config.vm.boot_timeout" value) time period.
If you look above, you should be able to see the error(s) that
Vagrant had when attempting to connect to the machine. These errors
are usually good hints as to what may be wrong.
If you're using a custom box, make sure that networking is properly
working and you're able to connect to the machine. It is a common
problem that networking isn't setup properly in these boxes.
Verify that authentication configurations are also setup properly,
as well.
If the box appears to be booting properly, you may want to increase
the timeout ("config.vm.boot_timeout") value.
Things I have tried:
Ensuring virtualization is enabled in BIOS
Increasing boot timeout in vagrantfile
Ensuring the VMs network settings are correct in Virtualbox (NAT adapter with cable connected)
Using vb.gui = true to watch the VM boot. It boots fine and waits at the login screen.
Using --debug flag on vagrant up. This doesn't give any obvious errors that I found, though before timing out it runs VBoxManage showvminfo --machinereadable several hundred times, resulting in a log file of over 80k lines.
As well as several other things I forgot to write down. I'm out of ideas and quite new to Vagrant, so I don't really know what the next step of troubleshooting this is. Any help would be appreciated.
Edit: Not sure why I didn't think to do it myself, but Marco gave me the idea to try to ssh directly to the VM. I tried doing so using the key file in "/.vagrant.d/insecure_private_key" created by Vagrant, but it timed out. I then tried to simply ping the VM, but doing so gives a seemingly random mix of "Request timed out" and "Destination host unreachable", so there's probably a bigger network issue somewhere (my machine, the VM, or Virtualbox) I'm unaware of.

Answer 1

Are you declaring some kind of network for this box? Either private or public, but something?
Also, how long is your boot timeout? Go overboard and give it 900=>15mn.