diff --git a/cloudinit/sources/DataSourceOpenNebula.py b/cloudinit/sources/DataSourceOpenNebula.py
index 835486c6..b6eb8477 100644
--- a/cloudinit/sources/DataSourceOpenNebula.py
+++ b/cloudinit/sources/DataSourceOpenNebula.py
@@ -137,21 +137,30 @@ class OpenNebulaNetwork(object):
     def get_ip(self, dev, components):
         var_name = dev.upper() + '_IP'
         if var_name in self.context:
-            return self.context[var_name]
+            if self.context[var_name]:
+                return self.context[var_name]
+            else:
+                return '.'.join(components)
         else:
             return '.'.join(components)
 
     def get_mask(self, dev):
         var_name = dev.upper() + '_MASK'
         if var_name in self.context:
-            return self.context[var_name]
+            if self.context[var_name]:
+                return self.context[var_name]
+            else:
+                return '255.255.255.0'
         else:
             return '255.255.255.0'
 
     def get_network(self, dev, components):
         var_name = dev.upper() + '_NETWORK'
         if var_name in self.context:
-            return self.context[var_name]
+            if self.context[var_name]:
+                return self.context[var_name]
+            else:
+                return '.'.join(components[:-1]) + '.0'
         else:
             return '.'.join(components[:-1]) + '.0'