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/api/src/main/java/org/onlab/onos/net/DefaultHost.java b/core/api/src/main/java/org/onlab/onos/net/DefaultHost.java
index cb2e292..d8d6c62 100644
--- a/core/api/src/main/java/org/onlab/onos/net/DefaultHost.java
+++ b/core/api/src/main/java/org/onlab/onos/net/DefaultHost.java
@@ -1,7 +1,7 @@
 package org.onlab.onos.net;
 
 import org.onlab.onos.net.provider.ProviderId;
-import org.onlab.packet.IpPrefix;
+import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
@@ -20,8 +20,7 @@
     private final MacAddress mac;
     private final VlanId vlan;
     private final HostLocation location;
-    // FIXME: should be IpAddress
-    private final Set<IpPrefix> ips;
+    private final Set<IpAddress> ips;
 
     /**
      * Creates an end-station host using the supplied information.
@@ -35,13 +34,13 @@
      * @param annotations optional key/value annotations
      */
     public DefaultHost(ProviderId providerId, HostId id, MacAddress mac,
-                       VlanId vlan, HostLocation location, Set<IpPrefix> ips,
+                       VlanId vlan, HostLocation location, Set<IpAddress> ips,
                        Annotations... annotations) {
         super(providerId, id, annotations);
         this.mac = mac;
         this.vlan = vlan;
         this.location = location;
-        this.ips = new HashSet<IpPrefix>(ips);
+        this.ips = new HashSet<>(ips);
     }
 
     @Override
@@ -55,7 +54,7 @@
     }
 
     @Override
-    public Set<IpPrefix> ipAddresses() {
+    public Set<IpAddress> ipAddresses() {
         return Collections.unmodifiableSet(ips);
     }
 
diff --git a/core/api/src/main/java/org/onlab/onos/net/Host.java b/core/api/src/main/java/org/onlab/onos/net/Host.java
index 3a9bfa5..9d08591 100644
--- a/core/api/src/main/java/org/onlab/onos/net/Host.java
+++ b/core/api/src/main/java/org/onlab/onos/net/Host.java
@@ -1,6 +1,6 @@
 package org.onlab.onos.net;
 
-import org.onlab.packet.IpPrefix;
+import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
@@ -38,8 +38,7 @@
      *
      * @return set of IP addresses; empty if no IP address is bound
      */
-    // FIXME: Switch to IpAddress
-    Set<IpPrefix> ipAddresses();
+    Set<IpAddress> ipAddresses();
 
     /**
      * Returns the most recent host location where the host attaches to the
diff --git a/core/api/src/main/java/org/onlab/onos/net/host/DefaultHostDescription.java b/core/api/src/main/java/org/onlab/onos/net/host/DefaultHostDescription.java
index 71a952e..ae548e1 100644
--- a/core/api/src/main/java/org/onlab/onos/net/host/DefaultHostDescription.java
+++ b/core/api/src/main/java/org/onlab/onos/net/host/DefaultHostDescription.java
@@ -6,7 +6,7 @@
 import org.onlab.onos.net.AbstractDescription;
 import org.onlab.onos.net.HostLocation;
 import org.onlab.onos.net.SparseAnnotations;
-import org.onlab.packet.IpPrefix;
+import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
@@ -23,7 +23,7 @@
     private final MacAddress mac;
     private final VlanId vlan;
     private final HostLocation location;
-    private final Set<IpPrefix> ip;
+    private final Set<IpAddress> ip;
 
     /**
      * Creates a host description using the supplied information.
@@ -36,7 +36,8 @@
     public DefaultHostDescription(MacAddress mac, VlanId vlan,
                                   HostLocation location,
                                   SparseAnnotations... annotations) {
-        this(mac, vlan, location, Collections.<IpPrefix>emptySet(), annotations);
+        this(mac, vlan, location, Collections.<IpAddress>emptySet(),
+             annotations);
     }
 
     /**
@@ -49,7 +50,7 @@
      * @param annotations optional key/value annotations map
      */
     public DefaultHostDescription(MacAddress mac, VlanId vlan,
-                                  HostLocation location, IpPrefix ip,
+                                  HostLocation location, IpAddress ip,
                                   SparseAnnotations... annotations) {
         this(mac, vlan, location, ImmutableSet.of(ip), annotations);
     }
@@ -64,7 +65,7 @@
      * @param annotations optional key/value annotations map
      */
     public DefaultHostDescription(MacAddress mac, VlanId vlan,
-                                  HostLocation location, Set<IpPrefix> ip,
+                                  HostLocation location, Set<IpAddress> ip,
                                   SparseAnnotations... annotations) {
         super(annotations);
         this.mac = mac;
@@ -89,7 +90,7 @@
     }
 
     @Override
-    public Set<IpPrefix> ipAddress() {
+    public Set<IpAddress> ipAddress() {
         return ip;
     }
 
diff --git a/core/api/src/main/java/org/onlab/onos/net/host/HostDescription.java b/core/api/src/main/java/org/onlab/onos/net/host/HostDescription.java
index 258ce3d..c42dc03 100644
--- a/core/api/src/main/java/org/onlab/onos/net/host/HostDescription.java
+++ b/core/api/src/main/java/org/onlab/onos/net/host/HostDescription.java
@@ -4,7 +4,7 @@
 
 import org.onlab.onos.net.Description;
 import org.onlab.onos.net.HostLocation;
-import org.onlab.packet.IpPrefix;
+import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
@@ -39,7 +39,5 @@
      *
      * @return host IP address
      */
-    // FIXME: Switch to IpAddress
-    Set<IpPrefix> ipAddress();
-
+    Set<IpAddress> ipAddress();
 }
diff --git a/core/api/src/main/java/org/onlab/onos/net/host/HostService.java b/core/api/src/main/java/org/onlab/onos/net/host/HostService.java
index 09034eb..f18569f 100644
--- a/core/api/src/main/java/org/onlab/onos/net/host/HostService.java
+++ b/core/api/src/main/java/org/onlab/onos/net/host/HostService.java
@@ -7,7 +7,6 @@
 import org.onlab.onos.net.Host;
 import org.onlab.onos.net.HostId;
 import org.onlab.packet.IpAddress;
-import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
@@ -60,7 +59,7 @@
      * @param ip ip address
      * @return set of hosts with the given IP
      */
-    Set<Host> getHostsByIp(IpPrefix ip);
+    Set<Host> getHostsByIp(IpAddress ip);
 
     // TODO: consider adding Host getHostByIp(IpAddress ip, VlanId vlan);
 
diff --git a/core/api/src/main/java/org/onlab/onos/net/host/HostStore.java b/core/api/src/main/java/org/onlab/onos/net/host/HostStore.java
index b27b697..535479c8 100644
--- a/core/api/src/main/java/org/onlab/onos/net/host/HostStore.java
+++ b/core/api/src/main/java/org/onlab/onos/net/host/HostStore.java
@@ -6,7 +6,7 @@
 import org.onlab.onos.net.HostId;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.store.Store;
-import org.onlab.packet.IpPrefix;
+import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
@@ -82,8 +82,7 @@
      * @param ip ip address
      * @return set of hosts with the given IP
      */
-    // FIXME: Switch to IpAddress
-    Set<Host> getHosts(IpPrefix ip);
+    Set<Host> getHosts(IpAddress ip);
 
     /**
      * Returns the set of hosts whose location falls on the given connection point.
diff --git a/core/api/src/main/java/org/onlab/onos/net/proxyarp/ProxyArpService.java b/core/api/src/main/java/org/onlab/onos/net/proxyarp/ProxyArpService.java
index 1e29a02..f49b5cf 100644
--- a/core/api/src/main/java/org/onlab/onos/net/proxyarp/ProxyArpService.java
+++ b/core/api/src/main/java/org/onlab/onos/net/proxyarp/ProxyArpService.java
@@ -3,7 +3,7 @@
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.packet.PacketContext;
 import org.onlab.packet.Ethernet;
-import org.onlab.packet.IpPrefix;
+import org.onlab.packet.IpAddress;
 
 /**
  * Service for processing arp requests on behalf of applications.
@@ -17,7 +17,7 @@
      * @param addr a ip address
      * @return true if know, false otherwise
      */
-    boolean known(IpPrefix addr);
+    boolean known(IpAddress addr);
 
     /**
      * Sends a reply for a given request. If the host is not known then the arp