diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionType.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionType.java
new file mode 100644
index 0000000..747a85b
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionType.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.net.flow.instructions;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.MoreObjects;
+
+import java.util.Objects;
+
+/**
+ * Type of extension instructions.
+ */
+@Beta
+public final class ExtensionType {
+
+    /**
+     * A list of well-known named extension instruction type codes.
+     */
+    public enum ExtensionTypes {
+        // TODO fix type numbers to include experimenter id
+        NICIRA_SET_TUNNEL_DST(31);
+
+        private ExtensionType type;
+
+        /**
+         * Creates a new named extension instruction type.
+         *
+         * @param type type code
+         */
+        ExtensionTypes(int type) {
+            this.type = new ExtensionType(type);
+        }
+
+        /**
+         * Gets the extension type object for this named type code.
+         *
+         * @return extension type object
+         */
+        public ExtensionType type() {
+            return type;
+        }
+    }
+
+    private final int type;
+
+    /**
+     * Creates an extension type with the given int type code.
+     *
+     * @param type type code
+     */
+    public ExtensionType(int type) {
+        this.type = type;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(type);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof ExtensionType) {
+            final ExtensionType that = (ExtensionType) obj;
+            return this.type == that.type;
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(ExtensionType.class)
+                .add("type", type)
+                .toString();
+    }
+}