Merge pull request #2539 from bearstech/debian_ifdown_ifup

guests/debian: ifdown is not enough for network config

plugins/guests/debian/cap/configure_networks.rb

@@ -44,6 +44,7 @@ module VagrantPlugins
             # SSH never dies.
             interfaces.each do |interface|
               comm.sudo("/sbin/ifdown eth#{interface} 2> /dev/null")
+              comm.sudo("/sbin/ip addr flush dev eth#{interface} 2> /dev/null")
             end
 
             comm.sudo("cat /tmp/vagrant-network-entry >> /etc/network/interfaces")