Added APIs for binding address information to ports and for monitoring hosts/ips
diff --git a/core/api/src/main/java/org/onlab/onos/net/host/PortAddresses.java b/core/api/src/main/java/org/onlab/onos/net/host/PortAddresses.java
new file mode 100644
index 0000000..16cc2b1
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/host/PortAddresses.java
@@ -0,0 +1,32 @@
+package org.onlab.onos.net.host;
+
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.MacAddress;
+
+/**
+ * Represents address information bound to a port.
+ */
+public interface PortAddresses {
+
+ /**
+ * Returns the connection point this address information is bound to.
+ *
+ * @return the connection point
+ */
+ ConnectPoint connectPoint();
+
+ /**
+ * Returns the IP address bound to the port.
+ *
+ * @return the IP address
+ */
+ IpAddress ip();
+
+ /**
+ * Returns the MAC address bound to the port.
+ *
+ * @return the MAC address if one is bound, otherwise null
+ */
+ MacAddress mac();
+}