diff --git a/core/java/android/net/IpPrefix.java b/core/java/android/net/IpPrefix.java
index 6b4f2d5..6e2654e 100644
--- a/core/java/android/net/IpPrefix.java
+++ b/core/java/android/net/IpPrefix.java
@@ -20,6 +20,8 @@
 import android.os.Parcelable;
 import android.util.Pair;
 
+import java.net.Inet4Address;
+import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.Arrays;
@@ -185,6 +187,20 @@
     }
 
     /**
+     * @hide
+     */
+    public boolean isIPv6() {
+        return getAddress() instanceof Inet6Address;
+    }
+
+    /**
+     * @hide
+     */
+    public boolean isIPv4() {
+        return getAddress() instanceof Inet4Address;
+    }
+
+    /**
      * Returns a string representation of this {@code IpPrefix}.
      *
      * @return a string such as {@code "192.0.2.0/24"} or {@code "2001:db8:1:2::/64"}.
diff --git a/core/java/android/net/LinkAddress.java b/core/java/android/net/LinkAddress.java
index 62de991..bcfe938 100644
--- a/core/java/android/net/LinkAddress.java
+++ b/core/java/android/net/LinkAddress.java
@@ -76,7 +76,7 @@
      * RFC 6724 section 3.2.
      * @hide
      */
-    static int scopeForUnicastAddress(InetAddress addr) {
+    private static int scopeForUnicastAddress(InetAddress addr) {
         if (addr.isAnyLocalAddress()) {
             return RT_SCOPE_HOST;
         }
@@ -101,7 +101,7 @@
      * Per RFC 4193 section 8, fc00::/7 identifies these addresses.
      */
     private boolean isIPv6ULA() {
-        if (address instanceof Inet6Address) {
+        if (isIPv6()) {
             byte[] bytes = address.getAddress();
             return ((bytes[0] & (byte)0xfe) == (byte)0xfc);
         }
@@ -109,13 +109,29 @@
     }
 
     /**
+     * @return true if the address is IPv6.
+     * @hide
+     */
+    public boolean isIPv6() {
+        return address instanceof Inet6Address;
+    }
+
+    /**
+     * @return true if the address is IPv4 or is a mapped IPv4 address.
+     * @hide
+     */
+    public boolean isIPv4() {
+        return address instanceof Inet4Address;
+    }
+
+    /**
      * Utility function for the constructors.
      */
     private void init(InetAddress address, int prefixLength, int flags, int scope) {
         if (address == null ||
                 address.isMulticastAddress() ||
                 prefixLength < 0 ||
-                ((address instanceof Inet4Address) && prefixLength > 32) ||
+                (address instanceof Inet4Address && prefixLength > 32) ||
                 (prefixLength > 128)) {
             throw new IllegalArgumentException("Bad LinkAddress params " + address +
                     "/" + prefixLength);
@@ -184,6 +200,7 @@
      */
     public LinkAddress(String address, int flags, int scope) {
         // This may throw an IllegalArgumentException; catching it is the caller's responsibility.
+        // TODO: consider rejecting mapped IPv4 addresses such as "::ffff:192.0.2.5/24".
         Pair<InetAddress, Integer> ipAndMask = NetworkUtils.parseIpAndMask(address);
         init(ipAndMask.first, ipAndMask.second, flags, scope);
     }
diff --git a/core/tests/coretests/src/android/net/IpPrefixTest.java b/tests/net/java/android/net/IpPrefixTest.java
similarity index 93%
rename from core/tests/coretests/src/android/net/IpPrefixTest.java
rename to tests/net/java/android/net/IpPrefixTest.java
index 4f2387d..b5b2c07 100644
--- a/core/tests/coretests/src/android/net/IpPrefixTest.java
+++ b/tests/net/java/android/net/IpPrefixTest.java
@@ -16,18 +16,27 @@
 
 package android.net;
 
-import android.net.IpPrefix;
-import android.os.Parcel;
-import android.test.suitebuilder.annotation.SmallTest;
-import java.net.InetAddress;
-import java.util.Random;
-import junit.framework.TestCase;
-
-import static android.test.MoreAsserts.assertNotEqual;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
-public class IpPrefixTest extends TestCase {
+import android.os.Parcel;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+
+import java.net.InetAddress;
+import java.util.Random;
+
+import org.junit.runner.RunWith;
+import org.junit.Test;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class IpPrefixTest {
 
     private static InetAddress Address(String addr) {
         return InetAddress.parseNumericAddress(addr);
@@ -42,7 +51,7 @@
         (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0xa0
     };
 
-    @SmallTest
+    @Test
     public void testConstructor() {
         IpPrefix p;
         try {
@@ -103,6 +112,7 @@
         } catch(IllegalArgumentException expected) {}
     }
 
+    @Test
     public void testTruncation() {
         IpPrefix p;
 
@@ -170,7 +180,7 @@
         assertFalse(o2.equals(o1));
     }
 
-    @SmallTest
+    @Test
     public void testEquals() {
         IpPrefix p1, p2;
 
@@ -212,7 +222,7 @@
         assertAreNotEqual(p1, p2);
     }
 
-    @SmallTest
+    @Test
     public void testContains() {
         IpPrefix p = new IpPrefix("2001:db8:f00::ace:d00d/127");
         assertTrue(p.contains(Address("2001:db8:f00::ace:d00c")));
@@ -240,7 +250,7 @@
         assertFalse(ipv4Default.contains(Address("2001:db8::f00")));
     }
 
-    @SmallTest
+    @Test
     public void testHashCode() {
         IpPrefix p = new IpPrefix(new byte[4], 0);
         Random random = new Random();
@@ -261,12 +271,12 @@
               assertEquals(p.hashCode(), oldP.hashCode());
             }
             if (p.hashCode() != oldP.hashCode()) {
-              assertNotEqual(p, oldP);
+              assertNotEquals(p, oldP);
             }
         }
     }
 
-    @SmallTest
+    @Test
     public void testHashCodeIsNotConstant() {
         IpPrefix[] prefixes = {
             new IpPrefix("2001:db8:f00::ace:d00d/127"),
@@ -276,12 +286,12 @@
         };
         for (int i = 0; i < prefixes.length; i++) {
           for (int j = i + 1; j < prefixes.length; j++) {
-            assertNotEqual(prefixes[i].hashCode(), prefixes[j].hashCode());
+            assertNotEquals(prefixes[i].hashCode(), prefixes[j].hashCode());
           }
         }
     }
 
-    @SmallTest
+    @Test
     public void testMappedAddressesAreBroken() {
         // 192.0.2.0/24 != ::ffff:c000:0204/120, but because we use InetAddress,
         // we are unable to comprehend that.
@@ -318,13 +328,16 @@
       assertEquals(p, p2);
     }
 
+    @Test
     public void testParceling() {
         IpPrefix p;
 
         p = new IpPrefix("2001:4860:db8::/64");
         assertParcelingIsLossless(p);
+        assertTrue(p.isIPv6());
 
         p = new IpPrefix("192.0.2.0/25");
         assertParcelingIsLossless(p);
+        assertTrue(p.isIPv4());
     }
 }
diff --git a/core/tests/coretests/src/android/net/LinkAddressTest.java b/tests/net/java/android/net/LinkAddressTest.java
similarity index 91%
rename from core/tests/coretests/src/android/net/LinkAddressTest.java
rename to tests/net/java/android/net/LinkAddressTest.java
index adf8d95..c1ad946 100644
--- a/core/tests/coretests/src/android/net/LinkAddressTest.java
+++ b/tests/net/java/android/net/LinkAddressTest.java
@@ -16,6 +16,23 @@
 
 package android.net;
 
+import static android.system.OsConstants.IFA_F_DADFAILED;
+import static android.system.OsConstants.IFA_F_DEPRECATED;
+import static android.system.OsConstants.IFA_F_OPTIMISTIC;
+import static android.system.OsConstants.IFA_F_PERMANENT;
+import static android.system.OsConstants.IFA_F_TEMPORARY;
+import static android.system.OsConstants.IFA_F_TENTATIVE;
+import static android.system.OsConstants.RT_SCOPE_HOST;
+import static android.system.OsConstants.RT_SCOPE_LINK;
+import static android.system.OsConstants.RT_SCOPE_SITE;
+import static android.system.OsConstants.RT_SCOPE_UNIVERSE;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
@@ -27,44 +44,35 @@
 import java.util.Comparator;
 import java.util.List;
 
-import android.net.LinkAddress;
 import android.os.Parcel;
-import android.test.AndroidTestCase;
-import static android.test.MoreAsserts.assertNotEqual;
-import android.test.suitebuilder.annotation.SmallTest;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
 
-import static android.system.OsConstants.IFA_F_DADFAILED;
-import static android.system.OsConstants.IFA_F_DEPRECATED;
-import static android.system.OsConstants.IFA_F_OPTIMISTIC;
-import static android.system.OsConstants.IFA_F_PERMANENT;
-import static android.system.OsConstants.IFA_F_TEMPORARY;
-import static android.system.OsConstants.IFA_F_TENTATIVE;
-import static android.system.OsConstants.RT_SCOPE_HOST;
-import static android.system.OsConstants.RT_SCOPE_LINK;
-import static android.system.OsConstants.RT_SCOPE_SITE;
-import static android.system.OsConstants.RT_SCOPE_UNIVERSE;
+import org.junit.runner.RunWith;
+import org.junit.Test;
 
-/**
- * Tests for {@link LinkAddress}.
- */
-public class LinkAddressTest extends AndroidTestCase {
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class LinkAddressTest {
 
     private static final String V4 = "192.0.2.1";
     private static final String V6 = "2001:db8::1";
     private static final InetAddress V4_ADDRESS = NetworkUtils.numericToInetAddress(V4);
     private static final InetAddress V6_ADDRESS = NetworkUtils.numericToInetAddress(V6);
 
+    @Test
     public void testConstants() {
         // RT_SCOPE_UNIVERSE = 0, but all the other constants should be nonzero.
-        assertNotEqual(0, RT_SCOPE_HOST);
-        assertNotEqual(0, RT_SCOPE_LINK);
-        assertNotEqual(0, RT_SCOPE_SITE);
+        assertNotEquals(0, RT_SCOPE_HOST);
+        assertNotEquals(0, RT_SCOPE_LINK);
+        assertNotEquals(0, RT_SCOPE_SITE);
 
-        assertNotEqual(0, IFA_F_DEPRECATED);
-        assertNotEqual(0, IFA_F_PERMANENT);
-        assertNotEqual(0, IFA_F_TENTATIVE);
+        assertNotEquals(0, IFA_F_DEPRECATED);
+        assertNotEquals(0, IFA_F_PERMANENT);
+        assertNotEquals(0, IFA_F_TENTATIVE);
     }
 
+    @Test
     public void testConstructors() throws SocketException {
         LinkAddress address;
 
@@ -74,12 +82,14 @@
         assertEquals(25, address.getPrefixLength());
         assertEquals(0, address.getFlags());
         assertEquals(RT_SCOPE_UNIVERSE, address.getScope());
+        assertTrue(address.isIPv4());
 
         address = new LinkAddress(V6_ADDRESS, 127);
         assertEquals(V6_ADDRESS, address.getAddress());
         assertEquals(127, address.getPrefixLength());
         assertEquals(0, address.getFlags());
         assertEquals(RT_SCOPE_UNIVERSE, address.getScope());
+        assertTrue(address.isIPv6());
 
         // Nonsensical flags/scopes or combinations thereof are acceptable.
         address = new LinkAddress(V6 + "/64", IFA_F_DEPRECATED | IFA_F_PERMANENT, RT_SCOPE_LINK);
@@ -87,12 +97,14 @@
         assertEquals(64, address.getPrefixLength());
         assertEquals(IFA_F_DEPRECATED | IFA_F_PERMANENT, address.getFlags());
         assertEquals(RT_SCOPE_LINK, address.getScope());
+        assertTrue(address.isIPv6());
 
         address = new LinkAddress(V4 + "/23", 123, 456);
         assertEquals(V4_ADDRESS, address.getAddress());
         assertEquals(23, address.getPrefixLength());
         assertEquals(123, address.getFlags());
         assertEquals(456, address.getScope());
+        assertTrue(address.isIPv4());
 
         // InterfaceAddress doesn't have a constructor. Fetch some from an interface.
         List<InterfaceAddress> addrs = NetworkInterface.getByName("lo").getInterfaceAddresses();
@@ -174,6 +186,7 @@
         } catch(IllegalArgumentException expected) {}
     }
 
+    @Test
     public void testAddressScopes() {
         assertEquals(RT_SCOPE_HOST, new LinkAddress("::/128").getScope());
         assertEquals(RT_SCOPE_HOST, new LinkAddress("0.0.0.0/32").getScope());
@@ -216,6 +229,7 @@
         assertFalse(l2 + " unexpectedly equal to " + l1, l2.equals(l1));
     }
 
+    @Test
     public void testEqualsAndSameAddressAs() {
         LinkAddress l1, l2, l3;
 
@@ -293,26 +307,17 @@
         assertIsSameAddressAs(l1, l2);
     }
 
+    @Test
     public void testHashCode() {
-        LinkAddress l;
+        LinkAddress l1, l2;
 
-        l = new LinkAddress(V4_ADDRESS, 23);
-        assertEquals(-982787, l.hashCode());
+        l1 = new LinkAddress(V4_ADDRESS, 23);
+        l2 = new LinkAddress(V4_ADDRESS, 23, 0, RT_SCOPE_HOST);
+        assertNotEquals(l1.hashCode(), l2.hashCode());
 
-        l = new LinkAddress(V4_ADDRESS, 23, 0, RT_SCOPE_HOST);
-        assertEquals(-971865, l.hashCode());
-
-        l = new LinkAddress(V4_ADDRESS, 27);
-        assertEquals(-982743, l.hashCode());
-
-        l = new LinkAddress(V6_ADDRESS, 64);
-        assertEquals(1076522926, l.hashCode());
-
-        l = new LinkAddress(V6_ADDRESS, 128);
-        assertEquals(1076523630, l.hashCode());
-
-        l = new LinkAddress(V6_ADDRESS, 128, IFA_F_TENTATIVE, RT_SCOPE_UNIVERSE);
-        assertEquals(1076524846, l.hashCode());
+        l1 = new LinkAddress(V6_ADDRESS, 128);
+        l2 = new LinkAddress(V6_ADDRESS, 128, IFA_F_TENTATIVE, RT_SCOPE_UNIVERSE);
+        assertNotEquals(l1.hashCode(), l2.hashCode());
     }
 
     private LinkAddress passThroughParcel(LinkAddress l) {
@@ -334,6 +339,7 @@
       assertEquals(l, l2);
     }
 
+    @Test
     public void testParceling() {
         LinkAddress l;
 
@@ -352,6 +358,7 @@
         assertFalse(msg, l.isGlobalPreferred());
     }
 
+    @Test
     public void testIsGlobalPreferred() {
         LinkAddress l;