diff --git a/config/default.yml b/config/default.yml
index 3dc13f1..596138b 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -27,6 +27,7 @@
   #                      compute nodes
   extraVars:
     - 'virtualbox_support=1'
+    - 'external_iface=eth0'
 
 otherServers:
   # Specifies the configuration for dynamically added compute nodes