diff --git a/scenario/scenario_base.py b/scenario/scenario_base.py
index dd25b89..dbd825b 100644
--- a/scenario/scenario_base.py
+++ b/scenario/scenario_base.py
@@ -25,6 +25,7 @@
         if not self.conf.fixed_network_name:
             raise self.skipException("No default network configured to test")
         self.net = self._get_network()
+        self.subnet_v4 = self._get_subnet_by_version(self.net)
 
         if not self.conf.image_ref:
             raise self.skipException("No image configured to test")