diff --git a/lib/vagrant/action/vm/sane_defaults.rb b/lib/vagrant/action/vm/sane_defaults.rb
index dd1068d91..f2dd31ab9 100644
--- a/lib/vagrant/action/vm/sane_defaults.rb
+++ b/lib/vagrant/action/vm/sane_defaults.rb
@@ -28,13 +28,34 @@ module Vagrant
           ]
           attempt_and_log(command, "Enabling the Host I/O cache on the SATA controller...")
 
-          # Enable the DNS proxy while in NAT mode.  This shields the guest
-          # VM from external DNS changs on the host machine.
-          command = [
-            "modifyvm", env[:vm].uuid,
-            "--natdnsproxy1", "on"
-          ]
-          attempt_and_log(command, "Enable the NAT DNS proxy on adapter 1...")
+          enable_dns_proxy = true
+          begin
+            contents = File.read("/etc/resolv.conf")
+
+            if contents =~ /^nameserver 127\.0\.0\.1$/
+              # The use of both natdnsproxy and natdnshostresolver break on
+              # Ubuntu 12.04 that uses resolvconf with localhost. When used
+              # VirtualBox will give the client dns server 10.0.2.3, while
+              # not binding to that address itself. Therefore disable this
+              # feature if host uses the resolvconf server 127.0.0.1
+              @logger.info("Disabling DNS proxy since resolv.conf contains 127.0.0.1")
+              enable_dns_proxy = false
+            end
+          rescue Errno::ENOENT; end
+
+          # Enable/disable the NAT DNS proxy as necessary
+          if enable_dns_proxy
+            command = [
+              "modifyvm", env[:vm].uuid,
+              "--natdnsproxy1", "on"
+            ]
+            attempt_and_log(command, "Enable the NAT DNS proxy on adapter 1...")
+          else
+            command = [ "modifyvm", env[:vm].uuid, "--natdnsproxy1", "off" ]
+            attempt_and_log(command, "Disable the NAT DNS proxy on adapter 1...")
+            command = [ "modifyvm", env[:vm].uuid, "--natdnshostresolver1", "off" ]
+            attempt_and_log(command, "Disable the NAT DNS resolver on adapter 1...")
+          end
 
           @app.call(env)
         end