diff --git a/tests/net/Android.bp b/tests/net/Android.bp
index c8ef82e..3ff862c 100644
--- a/tests/net/Android.bp
+++ b/tests/net/Android.bp
@@ -64,7 +64,7 @@
 android_test {
     name: "FrameworksNetTests",
     defaults: ["FrameworksNetTests-jni-defaults"],
-    srcs: ["java/**/*.java"],
+    srcs: ["java/**/*.java", "java/**/*.kt"],
     platform_apis: true,
     test_suites: ["device-tests"],
     certificate: "platform",
diff --git a/tests/net/java/com/android/server/LegacyTypeTrackerTest.kt b/tests/net/java/com/android/server/LegacyTypeTrackerTest.kt
new file mode 100644
index 0000000..d983b65
--- /dev/null
+++ b/tests/net/java/com/android/server/LegacyTypeTrackerTest.kt
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server
+
+import android.net.ConnectivityManager.TYPE_ETHERNET
+import android.net.ConnectivityManager.TYPE_MOBILE
+import android.net.ConnectivityManager.TYPE_WIFI
+import android.net.ConnectivityManager.TYPE_WIMAX
+import androidx.test.filters.SmallTest
+import androidx.test.runner.AndroidJUnit4
+import com.android.server.ConnectivityService.LegacyTypeTracker
+import com.android.server.connectivity.NetworkAgentInfo
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertSame
+import org.junit.Assert.assertTrue
+import org.junit.Assert.fail
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentMatchers.any
+import org.mockito.Mockito.doReturn
+import org.mockito.Mockito.mock
+
+const val UNSUPPORTED_TYPE = TYPE_WIMAX
+
+@RunWith(AndroidJUnit4::class)
+@SmallTest
+class LegacyTypeTrackerTest {
+    private val supportedTypes = arrayOf(TYPE_MOBILE, TYPE_WIFI, TYPE_ETHERNET)
+
+    private val mMockService = mock(ConnectivityService::class.java).apply {
+        doReturn(false).`when`(this).isDefaultNetwork(any())
+    }
+    private val mTracker = LegacyTypeTracker(mMockService).apply {
+        supportedTypes.forEach {
+            addSupportedType(it)
+        }
+    }
+
+    @Test
+    fun testSupportedTypes() {
+        try {
+            mTracker.addSupportedType(supportedTypes[0])
+            fail("Expected IllegalStateException")
+        } catch (expected: IllegalStateException) {}
+        supportedTypes.forEach {
+            assertTrue(mTracker.isTypeSupported(it))
+        }
+        assertFalse(mTracker.isTypeSupported(UNSUPPORTED_TYPE))
+    }
+
+    @Test
+    fun testAddNetwork() {
+        val mobileNai = mock(NetworkAgentInfo::class.java)
+        val wifiNai = mock(NetworkAgentInfo::class.java)
+        mTracker.add(TYPE_MOBILE, mobileNai)
+        mTracker.add(TYPE_WIFI, wifiNai)
+        assertSame(mTracker.getNetworkForType(TYPE_MOBILE), mobileNai)
+        assertSame(mTracker.getNetworkForType(TYPE_WIFI), wifiNai)
+        // Make sure adding a second NAI does not change the results.
+        val secondMobileNai = mock(NetworkAgentInfo::class.java)
+        mTracker.add(TYPE_MOBILE, secondMobileNai)
+        assertSame(mTracker.getNetworkForType(TYPE_MOBILE), mobileNai)
+        assertSame(mTracker.getNetworkForType(TYPE_WIFI), wifiNai)
+        // Make sure removing a network that wasn't added for this type is a no-op.
+        mTracker.remove(TYPE_MOBILE, wifiNai, false /* wasDefault */)
+        assertSame(mTracker.getNetworkForType(TYPE_MOBILE), mobileNai)
+        assertSame(mTracker.getNetworkForType(TYPE_WIFI), wifiNai)
+        // Remove the top network for mobile and make sure the second one becomes the network
+        // of record for this type.
+        mTracker.remove(TYPE_MOBILE, mobileNai, false /* wasDefault */)
+        assertSame(mTracker.getNetworkForType(TYPE_MOBILE), secondMobileNai)
+        assertSame(mTracker.getNetworkForType(TYPE_WIFI), wifiNai)
+        // Make sure adding a network for an unsupported type does not register it.
+        mTracker.add(UNSUPPORTED_TYPE, mobileNai)
+        assertNull(mTracker.getNetworkForType(UNSUPPORTED_TYPE))
+    }
+}