diff --git a/src/main/java/net/onrc/onos/core/topology/Device.java b/src/main/java/net/onrc/onos/core/topology/Device.java
index a3eaf8b..71eda74 100644
--- a/src/main/java/net/onrc/onos/core/topology/Device.java
+++ b/src/main/java/net/onrc/onos/core/topology/Device.java
@@ -14,7 +14,7 @@
  * immutable object, or a copy of the original "SB" In-memory Topology.
  */
 @JsonSerialize(using = DeviceSerializer.class)
-public interface Device {
+public interface Device extends ITopologyElement {
     /**
      * Get the device MAC address.
      *
diff --git a/src/main/java/net/onrc/onos/core/topology/ITopologyElement.java b/src/main/java/net/onrc/onos/core/topology/ITopologyElement.java
new file mode 100644
index 0000000..b9ce0d3
--- /dev/null
+++ b/src/main/java/net/onrc/onos/core/topology/ITopologyElement.java
@@ -0,0 +1,16 @@
+package net.onrc.onos.core.topology;
+
+// TODO give me a better name.
+/**
+ * Interface common to Topology element interfaces.
+ */
+public interface ITopologyElement {
+
+    // TODO The term Type is a bit confusing, may rename to something like layer
+    /**
+     * Returns the type of topology element.
+     *
+     * @return the type of the topology element
+     */
+    public String getType();
+}
diff --git a/src/main/java/net/onrc/onos/core/topology/Link.java b/src/main/java/net/onrc/onos/core/topology/Link.java
index 8cd7b82..f54ff51 100644
--- a/src/main/java/net/onrc/onos/core/topology/Link.java
+++ b/src/main/java/net/onrc/onos/core/topology/Link.java
@@ -10,7 +10,7 @@
  * Interface of Link object in the topology.
  */
 @JsonSerialize(using = LinkSerializer.class)
-public interface Link extends StringAttributes {
+public interface Link extends ITopologyElement, StringAttributes {
     /**
      * Gets the source switch for the link.
      *
diff --git a/src/main/java/net/onrc/onos/core/topology/Port.java b/src/main/java/net/onrc/onos/core/topology/Port.java
index a8df75f..0ca5cce 100644
--- a/src/main/java/net/onrc/onos/core/topology/Port.java
+++ b/src/main/java/net/onrc/onos/core/topology/Port.java
@@ -14,7 +14,7 @@
  * Interface of Port object in the topology.
  */
 @JsonSerialize(using = PortSerializer.class)
-public interface Port extends StringAttributes {
+public interface Port extends ITopologyElement, StringAttributes {
 
     /**
      * Gets the data path ID (dpid) of the switch, which this port is on.
diff --git a/src/main/java/net/onrc/onos/core/topology/Switch.java b/src/main/java/net/onrc/onos/core/topology/Switch.java
index f57de38..11f3f2c 100644
--- a/src/main/java/net/onrc/onos/core/topology/Switch.java
+++ b/src/main/java/net/onrc/onos/core/topology/Switch.java
@@ -14,7 +14,7 @@
  * Interface of Switch object in the topology.
  */
 @JsonSerialize(using = SwitchSerializer.class)
-public interface Switch extends StringAttributes {
+public interface Switch extends ITopologyElement, StringAttributes {
 
     /**
      * Gets the data path ID (dpid) of this switch.
diff --git a/src/main/java/net/onrc/onos/core/topology/TopologyObject.java b/src/main/java/net/onrc/onos/core/topology/TopologyObject.java
index 661f081..ccb266c 100644
--- a/src/main/java/net/onrc/onos/core/topology/TopologyObject.java
+++ b/src/main/java/net/onrc/onos/core/topology/TopologyObject.java
@@ -7,7 +7,7 @@
 /**
  * Base class for Topology Objects.
  */
-public abstract class TopologyObject {
+public abstract class TopologyObject implements ITopologyElement {
 
     /**
      * Topology instance this object belongs to.
@@ -30,6 +30,7 @@
      *
      * @return the type of the topology object
      */
+    @Override
     public abstract String getType();