Speeding up stuff.
HostDescription now passes up just a single IpAddress.
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 bc6e3e5..2e92dad 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
@@ -1,6 +1,5 @@
 package org.onlab.onos.net.host;
 
-import com.google.common.collect.ImmutableSet;
 import org.onlab.onos.net.AbstractDescription;
 import org.onlab.onos.net.HostLocation;
 import org.onlab.onos.net.SparseAnnotations;
@@ -8,9 +7,6 @@
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
-import java.util.HashSet;
-import java.util.Set;
-
 import static com.google.common.base.MoreObjects.toStringHelper;
 
 /**
@@ -22,7 +18,7 @@
     private final MacAddress mac;
     private final VlanId vlan;
     private final HostLocation location;
-    private final Set<IpPrefix> ips;
+    private final IpPrefix ip;
 
     /**
      * Creates a host description using the supplied information.
@@ -35,7 +31,7 @@
     public DefaultHostDescription(MacAddress mac, VlanId vlan,
                                   HostLocation location,
                                   SparseAnnotations... annotations) {
-        this(mac, vlan, location, new HashSet<IpPrefix>(), annotations);
+        this(mac, vlan, location, null, annotations);
     }
 
     /**
@@ -44,17 +40,17 @@
      * @param mac         host MAC address
      * @param vlan        host VLAN identifier
      * @param location    host location
-     * @param ips         of host IP addresses
+     * @param ip          host IP address
      * @param annotations optional key/value annotations map
      */
     public DefaultHostDescription(MacAddress mac, VlanId vlan,
-                                  HostLocation location, Set<IpPrefix> ips,
+                                  HostLocation location, IpPrefix ip,
                                   SparseAnnotations... annotations) {
         super(annotations);
         this.mac = mac;
         this.vlan = vlan;
         this.location = location;
-        this.ips = new HashSet<>(ips);
+        this.ip = ip;
     }
 
     @Override
@@ -73,8 +69,8 @@
     }
 
     @Override
-    public Set<IpPrefix> ipAddresses() {
-        return ImmutableSet.copyOf(ips);
+    public IpPrefix ipAddress() {
+        return ip;
     }
 
     @Override
@@ -83,7 +79,7 @@
                 .add("mac", mac)
                 .add("vlan", vlan)
                 .add("location", location)
-                .add("ipAddresses", ips)
+                .add("ipAddress", ip)
                 .toString();
     }
 
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 27014b6..f45a383 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
@@ -1,7 +1,5 @@
 package org.onlab.onos.net.host;
 
-import java.util.Set;
-
 import org.onlab.onos.net.Description;
 import org.onlab.onos.net.HostLocation;
 import org.onlab.packet.IpPrefix;
@@ -35,10 +33,10 @@
     HostLocation location();
 
     /**
-     * Returns zero or more IP address(es) associated with this host's MAC.
+     * Returns the IP address associated with this host's MAC.
      *
-     * @return a set of IP addresses.
+     * @return host IP address
      */
-    Set<IpPrefix> ipAddresses();
+    IpPrefix ipAddress();
 
 }
diff --git a/core/api/src/test/java/org/onlab/onos/event/AbstractEventAccumulatorTest.java b/core/api/src/test/java/org/onlab/onos/event/AbstractEventAccumulatorTest.java
index 9e561bf..ed18195 100644
--- a/core/api/src/test/java/org/onlab/onos/event/AbstractEventAccumulatorTest.java
+++ b/core/api/src/test/java/org/onlab/onos/event/AbstractEventAccumulatorTest.java
@@ -45,15 +45,18 @@
     public void timeTrigger() {
         TestAccumulator accumulator = new TestAccumulator();
         accumulator.add(new TestEvent(FOO, "a"));
-        delay(40);
+        delay(30);
         assertTrue("should not have fired yet", accumulator.batch.isEmpty());
         accumulator.add(new TestEvent(FOO, "b"));
-        delay(40);
+        delay(30);
         assertTrue("should not have fired yet", accumulator.batch.isEmpty());
         accumulator.add(new TestEvent(FOO, "c"));
-        delay(40);
+        delay(30);
+        assertTrue("should not have fired yet", accumulator.batch.isEmpty());
+        accumulator.add(new TestEvent(FOO, "d"));
+        delay(30);
         assertFalse("should have fired", accumulator.batch.isEmpty());
-        assertEquals("incorrect batch", "abc", accumulator.batch);
+        assertEquals("incorrect batch", "abcd", accumulator.batch);
     }
 
     @Test
diff --git a/core/api/src/test/java/org/onlab/onos/net/host/DefualtHostDecriptionTest.java b/core/api/src/test/java/org/onlab/onos/net/host/DefualtHostDecriptionTest.java
index 1b00be7..5ae7c27 100644
--- a/core/api/src/test/java/org/onlab/onos/net/host/DefualtHostDecriptionTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/host/DefualtHostDecriptionTest.java
@@ -1,10 +1,5 @@
 package org.onlab.onos.net.host;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
-import java.util.Set;
-
 import org.junit.Test;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.HostLocation;
@@ -13,7 +8,8 @@
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
-import com.google.common.collect.Sets;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 /**
  * Test for the default host description.
@@ -22,24 +18,22 @@
 
     private static final MacAddress MAC = MacAddress.valueOf("00:00:11:00:00:01");
     private static final VlanId VLAN = VlanId.vlanId((short) 10);
+    private static final IpPrefix IP = IpPrefix.valueOf("10.0.0.1");
+
     private static final HostLocation LOC = new HostLocation(
-                DeviceId.deviceId("of:foo"),
-                PortNumber.portNumber(100),
-                123L
-            );
-    private static final Set<IpPrefix> IPS = Sets.newHashSet(
-                IpPrefix.valueOf("10.0.0.1"),
-                IpPrefix.valueOf("10.0.0.2")
-            );
+            DeviceId.deviceId("of:foo"),
+            PortNumber.portNumber(100),
+            123L
+    );
 
     @Test
     public void basics() {
         HostDescription host =
-                new DefaultHostDescription(MAC, VLAN, LOC, IPS);
+                new DefaultHostDescription(MAC, VLAN, LOC, IP);
         assertEquals("incorrect mac", MAC, host.hwAddress());
         assertEquals("incorrect vlan", VLAN, host.vlan());
         assertEquals("incorrect location", LOC, host.location());
-        assertTrue("incorrect ip's", IPS.equals(host.ipAddresses()));
+        assertEquals("incorrect ip's", IP, host.ipAddress());
         assertTrue("incorrect toString", host.toString().contains("vlan=10"));
     }