diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingSnatHandler.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingSnatHandler.java
index 1fa1148..03486c0 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingSnatHandler.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingSnatHandler.java
@@ -1459,8 +1459,14 @@
             }
 
             if (getStatefulSnatFlag() && osNode.type() == GATEWAY) {
-                instancePortService.instancePorts().forEach(instPort ->
-                        setGatewayToInstanceDownstreamRule(osNode, instPort, true));
+                instancePortService.instancePorts().forEach(instPort -> {
+                    Type netType = osNetworkAdminService.networkType(instPort.networkId());
+
+                    if (netType == FLAT) {
+                        return;
+                    }
+                    setGatewayToInstanceDownstreamRule(osNode, instPort, true);
+                });
             }
         }
 
@@ -1470,8 +1476,15 @@
             }
 
             if (getStatefulSnatFlag() && osNode.type() == GATEWAY) {
-                instancePortService.instancePorts().forEach(instPort ->
-                        setGatewayToInstanceDownstreamRule(osNode, instPort, false));
+                instancePortService.instancePorts().forEach(instPort -> {
+                    Type netType = osNetworkAdminService.networkType(instPort.networkId());
+
+                    if (netType == FLAT) {
+                        return;
+                    }
+
+                    setGatewayToInstanceDownstreamRule(osNode, instPort, false);
+                });
             }
         }