diff -r 912a5cb75c80 tools/python/xen/xend/server/netif.py
--- a/tools/python/xen/xend/server/netif.py	Wed Sep 19 15:49:56 2007 +0100
+++ b/tools/python/xen/xend/server/netif.py	Thu Sep 27 12:22:19 2007 -0400
@@ -108,17 +108,15 @@ class NetifController(DevController):
         ipaddr  = config.get('ip')
         model   = config.get('model')
 
-        if not typ:
-            typ = xoptions.netback_type
-
         if not mac:
             raise VmError("MAC address not specified or generated.")
 
         devid = self.allocateDeviceID()
 
         back = { 'script' : script,
-                 'mac'    : mac,
-                 'type'   : typ }
+                 'mac'    : mac }
+        if typ:
+            back['type'] = typ
         if ipaddr:
             back['ip'] = ipaddr
         if bridge: