Replaced IpPrefix and IpAddress in the following methods
and cleanup related code:

 - Host.ipAddresses()
 - DefaultHost.ipAddresses()
 - HostDescription.ipAddress()
 - DefaultHostDescription.ipAddress()
 - HostService.getHostsByIp()
 - HostManager.getHostsByIp()
 - HostStore.getHosts()
 - GossipHostStore.getHosts()
 - SimpleHostStore.getHosts()
 - ProxyArpService.known()
 - ProxyArpManager.known()

As a result of the above cleanup, the "hosts" CLI command outputs
the IP addresses as "1.2.3.4" instead of "1.2.3.4/32".

Also, the following REST calls might be affected as well with
the above format replacement:
  - REST POST: config/topology
  - REST GET: topology/graph
diff --git a/core/net/src/main/java/org/onlab/onos/net/host/impl/HostManager.java b/core/net/src/main/java/org/onlab/onos/net/host/impl/HostManager.java
index 4f9bcbb..e4d158d 100644
--- a/core/net/src/main/java/org/onlab/onos/net/host/impl/HostManager.java
+++ b/core/net/src/main/java/org/onlab/onos/net/host/impl/HostManager.java
@@ -33,7 +33,6 @@
 import org.onlab.onos.net.provider.AbstractProviderRegistry;
 import org.onlab.onos.net.provider.AbstractProviderService;
 import org.onlab.packet.IpAddress;
-import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 import org.slf4j.Logger;
@@ -121,7 +120,7 @@
     }
 
     @Override
-    public Set<Host> getHostsByIp(IpPrefix ip) {
+    public Set<Host> getHostsByIp(IpAddress ip) {
         checkNotNull(ip, "IP address cannot be null");
         return store.getHosts(ip);
     }
diff --git a/core/net/src/main/java/org/onlab/onos/net/host/impl/HostMonitor.java b/core/net/src/main/java/org/onlab/onos/net/host/impl/HostMonitor.java
index a624c07..e92440f 100644
--- a/core/net/src/main/java/org/onlab/onos/net/host/impl/HostMonitor.java
+++ b/core/net/src/main/java/org/onlab/onos/net/host/impl/HostMonitor.java
@@ -129,10 +129,7 @@
     @Override
     public void run(Timeout timeout) throws Exception {
         for (IpAddress ip : monitoredAddresses) {
-            // TODO have to convert right now because the HostService API uses IpPrefix
-            IpPrefix prefix = IpPrefix.valueOf(ip.toOctets());
-
-            Set<Host> hosts = hostManager.getHostsByIp(prefix);
+            Set<Host> hosts = hostManager.getHostsByIp(ip);
 
             if (hosts.isEmpty()) {
                 sendArpRequest(ip);
diff --git a/core/net/src/main/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManager.java b/core/net/src/main/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManager.java
index 735c109..3ba1c8a 100644
--- a/core/net/src/main/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManager.java
+++ b/core/net/src/main/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManager.java
@@ -99,7 +99,7 @@
     }
 
     @Override
-    public boolean known(IpPrefix addr) {
+    public boolean known(IpAddress addr) {
         checkNotNull(addr, MAC_ADDR_NULL);
         Set<Host> hosts = hostService.getHostsByIp(addr);
         return !hosts.isEmpty();
@@ -150,7 +150,7 @@
         // Continue with normal proxy ARP case
 
         VlanId vlan = VlanId.vlanId(eth.getVlanID());
-        Set<Host> hosts = hostService.getHostsByIp(IpPrefix.valueOf(arp
+        Set<Host> hosts = hostService.getHostsByIp(IpAddress.valueOf(arp
                 .getTargetProtocolAddress()));
 
         Host dst = null;
@@ -170,8 +170,7 @@
         }
 
         // TODO find the correct IP address
-        IpAddress ipAddress =
-            dst.ipAddresses().iterator().next().toIpAddress();
+        IpAddress ipAddress = dst.ipAddresses().iterator().next();
         Ethernet arpReply = buildArpReply(ipAddress, dst.mac(), eth);
         // TODO: check send status with host service.
         sendTo(arpReply, src.location());
diff --git a/core/net/src/test/java/org/onlab/onos/net/host/impl/HostManagerTest.java b/core/net/src/test/java/org/onlab/onos/net/host/impl/HostManagerTest.java
index c20da19..67e6cc4 100644
--- a/core/net/src/test/java/org/onlab/onos/net/host/impl/HostManagerTest.java
+++ b/core/net/src/test/java/org/onlab/onos/net/host/impl/HostManagerTest.java
@@ -58,8 +58,8 @@
     private static final HostId HID1 = HostId.hostId(MAC1, VLAN1);
     private static final HostId HID2 = HostId.hostId(MAC2, VLAN1);
 
-    private static final IpPrefix IP1 = IpPrefix.valueOf("10.0.0.1");
-    private static final IpPrefix IP2 = IpPrefix.valueOf("10.0.0.2");
+    private static final IpAddress IP1 = IpAddress.valueOf("10.0.0.1");
+    private static final IpAddress IP2 = IpAddress.valueOf("10.0.0.2");
 
     private static final DeviceId DID1 = DeviceId.deviceId("of:001");
     private static final DeviceId DID2 = DeviceId.deviceId("of:002");
@@ -115,7 +115,7 @@
     }
 
     private void detect(HostId hid, MacAddress mac, VlanId vlan,
-                        HostLocation loc, IpPrefix ip) {
+                        HostLocation loc, IpAddress ip) {
         HostDescription descr = new DefaultHostDescription(mac, vlan, loc, ip);
         providerService.hostDetected(hid, descr);
         assertNotNull("host should be found", mgr.getHost(hid));
diff --git a/core/net/src/test/java/org/onlab/onos/net/host/impl/HostMonitorTest.java b/core/net/src/test/java/org/onlab/onos/net/host/impl/HostMonitorTest.java
index 4b9d214..df211fb 100644
--- a/core/net/src/test/java/org/onlab/onos/net/host/impl/HostMonitorTest.java
+++ b/core/net/src/test/java/org/onlab/onos/net/host/impl/HostMonitorTest.java
@@ -46,9 +46,8 @@
 
 public class HostMonitorTest {
 
-    private IpAddress targetIpAddress = IpAddress.valueOf("10.0.0.1");
-    private IpPrefix targetIpPrefix = IpPrefix.valueOf(targetIpAddress.toOctets());
-
+    private static final IpAddress TARGET_IP_ADDR =
+        IpAddress.valueOf("10.0.0.1");
     private static final IpAddress SOURCE_ADDR =
         IpAddress.valueOf("10.0.0.99");
     private static final InterfaceIpAddress IA1 =
@@ -71,7 +70,7 @@
         replay(host);
 
         HostManager hostManager = createMock(HostManager.class);
-        expect(hostManager.getHostsByIp(targetIpPrefix))
+        expect(hostManager.getHostsByIp(TARGET_IP_ADDR))
                 .andReturn(Collections.singleton(host));
         replay(hostManager);
 
@@ -84,7 +83,7 @@
         hostMonitor = new HostMonitor(null, null, hostManager);
 
         hostMonitor.registerHostProvider(hostProvider);
-        hostMonitor.addMonitoringFor(targetIpAddress);
+        hostMonitor.addMonitoringFor(TARGET_IP_ADDR);
 
         hostMonitor.run(null);
 
@@ -115,7 +114,7 @@
         PortAddresses pa =
             new PortAddresses(cp, Collections.singleton(IA1), sourceMac);
 
-        expect(hostManager.getHostsByIp(targetIpPrefix))
+        expect(hostManager.getHostsByIp(TARGET_IP_ADDR))
                 .andReturn(Collections.<Host>emptySet()).anyTimes();
         expect(hostManager.getAddressBindingsForPort(cp))
                 .andReturn(pa).anyTimes();
@@ -127,7 +126,7 @@
         // Run the test
         hostMonitor = new HostMonitor(deviceService, packetService, hostManager);
 
-        hostMonitor.addMonitoringFor(targetIpAddress);
+        hostMonitor.addMonitoringFor(TARGET_IP_ADDR);
         hostMonitor.run(null);
 
 
@@ -150,7 +149,8 @@
         assertTrue(Arrays.equals(arp.getSenderProtocolAddress(),
                                  SOURCE_ADDR.toOctets()));
         assertTrue(Arrays.equals(arp.getSenderHardwareAddress(), sourceMac.toBytes()));
-        assertTrue(Arrays.equals(arp.getTargetProtocolAddress(), targetIpPrefix.toOctets()));
+        assertTrue(Arrays.equals(arp.getTargetProtocolAddress(),
+                                 TARGET_IP_ADDR.toOctets()));
     }
 
     class TestPacketService implements PacketService {
diff --git a/core/net/src/test/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManagerTest.java b/core/net/src/test/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManagerTest.java
index 76bf021..60fdb69 100644
--- a/core/net/src/test/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManagerTest.java
+++ b/core/net/src/test/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManagerTest.java
@@ -59,8 +59,8 @@
     private static final int NUM_ADDRESS_PORTS = NUM_DEVICES / 2;
     private static final int NUM_FLOOD_PORTS = 3;
 
-    private static final IpPrefix IP1 = IpPrefix.valueOf("192.168.1.1/24");
-    private static final IpPrefix IP2 = IpPrefix.valueOf("192.168.1.2/24");
+    private static final IpAddress IP1 = IpAddress.valueOf("192.168.1.1");
+    private static final IpAddress IP2 = IpAddress.valueOf("192.168.1.2");
 
     private static final ProviderId PID = new ProviderId("of", "foo");
 
@@ -214,7 +214,7 @@
     }
 
     /**
-     * Tests {@link ProxyArpManager#known(IpPrefix)} in the case where the
+     * Tests {@link ProxyArpManager#known(IpAddress)} in the case where the
      * IP address is not known.
      * Verifies the method returns false.
      */
@@ -227,7 +227,7 @@
     }
 
     /**
-     * Tests {@link ProxyArpManager#known(IpPrefix)} in the case where the
+     * Tests {@link ProxyArpManager#known(IpAddress)} in the case where the
      * IP address is known.
      * Verifies the method returns true.
      */
@@ -256,8 +256,8 @@
         Host requestor = new DefaultHost(PID, HID2, MAC2, VLAN1, getLocation(5),
                 Collections.singleton(IP2));
 
-        expect(hostService.getHostsByIp(IpPrefix.valueOf(IP1.toOctets())))
-                .andReturn(Collections.singleton(replyer));
+        expect(hostService.getHostsByIp(IP1))
+            .andReturn(Collections.singleton(replyer));
         expect(hostService.getHost(HID2)).andReturn(requestor);
 
         replay(hostService);
@@ -281,7 +281,7 @@
         Host requestor = new DefaultHost(PID, HID2, MAC2, VLAN1, getLocation(5),
                 Collections.singleton(IP2));
 
-        expect(hostService.getHostsByIp(IpPrefix.valueOf(IP1.toOctets())))
+        expect(hostService.getHostsByIp(IP1))
                 .andReturn(Collections.<Host>emptySet());
         expect(hostService.getHost(HID2)).andReturn(requestor);
 
@@ -308,7 +308,7 @@
         Host requestor = new DefaultHost(PID, HID2, MAC2, VLAN1, getLocation(5),
                 Collections.singleton(IP2));
 
-        expect(hostService.getHostsByIp(IpPrefix.valueOf(IP1.toOctets())))
+        expect(hostService.getHostsByIp(IP1))
                 .andReturn(Collections.singleton(replyer));
         expect(hostService.getHost(HID2)).andReturn(requestor);
 
@@ -323,9 +323,9 @@
 
     @Test
     public void testReplyToRequestForUs() {
-        IpPrefix theirIp = IpPrefix.valueOf("10.0.1.254/24");
-        IpPrefix ourFirstIp = IpPrefix.valueOf("10.0.1.1/24");
-        IpPrefix ourSecondIp = IpPrefix.valueOf("10.0.2.1/24");
+        IpAddress theirIp = IpAddress.valueOf("10.0.1.254");
+        IpAddress ourFirstIp = IpAddress.valueOf("10.0.1.1");
+        IpAddress ourSecondIp = IpAddress.valueOf("10.0.2.1");
         MacAddress ourMac = MacAddress.valueOf(1L);
 
         Host requestor = new DefaultHost(PID, HID2, MAC2, VLAN1, LOC1,
@@ -357,11 +357,11 @@
     public void testReplyExternalPortBadRequest() {
         replay(hostService); // no further host service expectations
 
-        IpPrefix theirIp = IpPrefix.valueOf("10.0.1.254/24");
+        IpAddress theirIp = IpAddress.valueOf("10.0.1.254");
 
         // Request for a valid external IP address but coming in the wrong port
         Ethernet arpRequest = buildArp(ARP.OP_REQUEST, MAC1, null, theirIp,
-                IpPrefix.valueOf("10.0.3.1"));
+                IpAddress.valueOf("10.0.3.1"));
         proxyArp.reply(arpRequest, LOC1);
         assertEquals(0, packetService.packets.size());
 
@@ -376,9 +376,9 @@
     public void testReplyToRequestFromUs() {
         replay(hostService); // no further host service expectations
 
-        IpPrefix ourIp = IpPrefix.valueOf("10.0.1.1/24");
+        IpAddress ourIp = IpAddress.valueOf("10.0.1.1");
         MacAddress ourMac = MacAddress.valueOf(1L);
-        IpPrefix theirIp = IpPrefix.valueOf("10.0.1.100/24");
+        IpAddress theirIp = IpAddress.valueOf("10.0.1.100");
 
         // This is a request from something inside our network (like a BGP
         // daemon) to an external host.
@@ -501,7 +501,7 @@
      * @return the ARP packet
      */
     private Ethernet buildArp(short opcode, MacAddress srcMac, MacAddress dstMac,
-            IpPrefix srcIp, IpPrefix dstIp) {
+            IpAddress srcIp, IpAddress dstIp) {
         Ethernet eth = new Ethernet();
 
         if (dstMac == null) {