diff --git a/Vagrantfile b/Vagrantfile
index 6fe482d..0f20e19 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -10,7 +10,6 @@ require 'yaml'
 conf = YAML.load(File.open('config.yaml'))
 
 def configure_vm(name, vm, conf)
-  vm.box = name
   vm.hostname = conf["#{name}_hostname"] or name
 
   # we do an L2 bridge directly onto the physical network, which means
@@ -66,18 +65,23 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
       configure_vm("compute1", compute1.vm, conf)
     end
   end
-  # The url from where the 'config.vm.box' box will be fetched if it
-  # doesn't already exist on the user's system.
+
+  # You can either name a Vagrant box you have locally added and use
+  # that as a starting point, or give a url from where the 'config.vm.box'
+  # box will be fetched.
   #
   # We start with the Ubuntu 12.04 upstream image, which will work. However
-  # building from this ever time is slow. So the recommended model is build
+  # building from this every time is slow. So the recommended model is build
   # the manager once, and recapture that. You do have to nuke a bunch of
   # network config information to make that capture work (documentation TBD).
-
-  config.vm.box_url = 'https://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-amd64-vagrant-disk1.box'
-  # this lets you use a locally accessible version faster
-  if conf['box_url']
-    config.vm.box_url = conf['box_url']
+  if conf['box_name']
+    config.vm.box = conf['box_name']
+  else
+      config.vm.box_url = 'https://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-amd64-vagrant-disk1.box'
+      # this lets you use a locally accessible version faster
+      if conf['box_url']
+        config.vm.box_url = conf['box_url']
+      end
   end
 
   # Create a forwarded port mapping which allows access to a specific port
diff --git a/config.yaml.sample b/config.yaml.sample
index a1309be..5a8a5e9 100644
--- a/config.yaml.sample
+++ b/config.yaml.sample
@@ -8,8 +8,15 @@ stack_sshkey: >
 setup_mode: devstack
 # what interface on the host should be used for a bridge
 # will often be eth0, but vagrant needs to know for sure
+# This needs to be the full string descriptor of the interface.
+# On some systems this can be something annoying like
+# 'en1: Wi-Fi (Airport)'. Vagrant will not use this setting
+# unless you get it exactly right.
 bridge_int: eth1
-# A non upstream url for the base box, used to speed things up
+# A non upstream for the base box, used to speed things up.
+# Choose one of box_name (for a locally added box) or box_url
+# for the url of a nearby box.
+#box_name: 'my.favorite'
 #box_url: http://gallifrey/vagrant/devstack-2014-02-19.box
 
 # Local devstack options