Index: xen-4.1.2-testing/tools/python/xen/xm/create.py
===================================================================
--- xen-4.1.2-testing.orig/tools/python/xen/xm/create.py
+++ xen-4.1.2-testing/tools/python/xen/xm/create.py
@@ -1337,9 +1337,8 @@ def preprocess_access_control(vals):
 
 def preprocess_ip(vals):
     if vals.ip or vals.dhcp != 'off':
-        dummy_nfs_server = '127.0.255.255'
         ip = (vals.ip
-          + ':' + (vals.nfs_server or dummy_nfs_server)
+          + ':' + (vals.nfs_server or '')
           + ':' + vals.gateway
           + ':' + vals.netmask
           + ':' + vals.hostname