diff --git a/apps/openstacknode/api/src/main/java/org/onosproject/openstacknode/api/Constants.java b/apps/openstacknode/api/src/main/java/org/onosproject/openstacknode/api/Constants.java
index 0422c65..e78d0e6 100644
--- a/apps/openstacknode/api/src/main/java/org/onosproject/openstacknode/api/Constants.java
+++ b/apps/openstacknode/api/src/main/java/org/onosproject/openstacknode/api/Constants.java
@@ -38,4 +38,10 @@
     public static final String DATA_IP = "dataIp";
     public static final String VLAN_INTF_NAME = "vlanPort";
     public static final String UPLINK_PORT = "uplinkPort";
+
+    public static final String FLAT = "flat";
+    public static final String VLAN = "vlan";
+    public static final String VXLAN = "vxlan";
+    public static final String GRE = "gre";
+    public static final String GENEVE = "geneve";
 }
\ No newline at end of file