diff --git a/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java b/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
index 75c2ad1..68c1c57 100644
--- a/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
+++ b/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
@@ -352,15 +352,6 @@
         assertFalse(mTestMap.isEmpty());
         mTestMap.clear();
         assertTrue(mTestMap.isEmpty());
-
-        // Clearing an already-closed map throws.
-        mTestMap.close();
-        try {
-            mTestMap.clear();
-            fail("clearing already-closed map should throw");
-        } catch (IllegalStateException expected) {
-            // ParcelFileDescriptor.getFd throws IllegalStateException: Already closed.
-        }
     }
 
     @Test
diff --git a/framework-t/src/android/net/IpSecManager.java b/framework-t/src/android/net/IpSecManager.java
index 9cb0947..9cceac2 100644
--- a/framework-t/src/android/net/IpSecManager.java
+++ b/framework-t/src/android/net/IpSecManager.java
@@ -817,10 +817,10 @@
          * </ol>
          *
          * @param underlyingNetwork the new {@link Network} that will carry traffic for this tunnel.
-         *     This network MUST never be the network exposing this IpSecTunnelInterface, otherwise
-         *     this method will throw an {@link IllegalArgumentException}. If the
-         *     IpSecTunnelInterface is later added to this network, all outbound traffic will be
-         *     blackholed.
+         *     This network MUST be a functional {@link Network} with valid {@link LinkProperties},
+         *     and MUST never be the network exposing this IpSecTunnelInterface, otherwise this
+         *     method will throw an {@link IllegalArgumentException}. If the IpSecTunnelInterface is
+         *     later added to this network, all outbound traffic will be blackholed.
          */
         // TODO: b/169171001 Update the documentation when transform migration is supported.
         // The purpose of making updating network and applying transforms separate is to leave open
@@ -962,7 +962,6 @@
      * IP header and IPsec Header on all inbound traffic).
      * <p>Applications should probably not use this API directly.
      *
-     *
      * @param tunnel The {@link IpSecManager#IpSecTunnelInterface} that will use the supplied
      *        transform.
      * @param direction the direction, {@link DIRECTION_OUT} or {@link #DIRECTION_IN} in which
diff --git a/framework/src/android/net/NetworkRequest.java b/framework/src/android/net/NetworkRequest.java
index 4f9d845..6245e07 100644
--- a/framework/src/android/net/NetworkRequest.java
+++ b/framework/src/android/net/NetworkRequest.java
@@ -220,7 +220,7 @@
          */
         public Builder(@NonNull final NetworkRequest request) {
             Objects.requireNonNull(request);
-            mNetworkCapabilities = request.networkCapabilities;
+            mNetworkCapabilities = new NetworkCapabilities(request.networkCapabilities);
             // If the caller constructed the builder from a request, it means the user
             // might explicitly want the capabilities from the request. Thus, the NOT_VCN_MANAGED
             // capabilities should not be touched later.
diff --git a/netd/BpfHandler.cpp b/netd/BpfHandler.cpp
index 08e66d9..42d0de5 100644
--- a/netd/BpfHandler.cpp
+++ b/netd/BpfHandler.cpp
@@ -104,6 +104,7 @@
     RETURN_IF_NOT_OK(mConfigurationMap.writeValue(CURRENT_STATS_MAP_CONFIGURATION_KEY, SELECT_MAP_A,
                                                   BPF_ANY));
     RETURN_IF_NOT_OK(mUidPermissionMap.init(UID_PERMISSION_MAP_PATH));
+    ALOGI("%s successfully", __func__);
 
     return netdutils::status::ok;
 }
@@ -233,7 +234,7 @@
     if (sock_cookie == NONEXISTENT_COOKIE) return -errno;
     base::Result<void> res = mCookieTagMap.deleteValue(sock_cookie);
     if (!res.ok()) {
-        ALOGE("Failed to untag socket: %s\n", strerror(res.error().code()));
+        ALOGE("Failed to untag socket: %s", strerror(res.error().code()));
         return -res.error().code();
     }
     return 0;
diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
index 4d605ce..6c7a15e 100644
--- a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
@@ -205,6 +205,10 @@
               configuration.error().message().c_str());
         return -configuration.error().code();
     }
+    if (configuration.value() != SELECT_MAP_A && configuration.value() != SELECT_MAP_B) {
+        ALOGE("%s unknown configuration value: %d", __func__, configuration.value());
+        return -EINVAL;
+    }
     const char* statsMapPath = STATS_MAP_PATH[configuration.value()];
     BpfMap<StatsKey, StatsValue> statsMap(statsMapPath);
     if (!statsMap.isValid()) {
diff --git a/service-t/src/com/android/server/IpSecService.java b/service-t/src/com/android/server/IpSecService.java
index 4bc40ea..16b9f1e 100644
--- a/service-t/src/com/android/server/IpSecService.java
+++ b/service-t/src/com/android/server/IpSecService.java
@@ -1452,6 +1452,11 @@
         final ConnectivityManager connectivityManager =
                 mContext.getSystemService(ConnectivityManager.class);
         final LinkProperties lp = connectivityManager.getLinkProperties(underlyingNetwork);
+        if (lp == null) {
+            throw new IllegalArgumentException(
+                    "LinkProperties is null. The underlyingNetwork may not be functional");
+        }
+
         if (tunnelInterfaceInfo.getInterfaceName().equals(lp.getInterfaceName())) {
             throw new IllegalArgumentException(
                     "Underlying network cannot be the network being exposed by this tunnel");
diff --git a/service-t/src/com/android/server/ethernet/EthernetConfigStore.java b/service-t/src/com/android/server/ethernet/EthernetConfigStore.java
index 6b623f4..6006539 100644
--- a/service-t/src/com/android/server/ethernet/EthernetConfigStore.java
+++ b/service-t/src/com/android/server/ethernet/EthernetConfigStore.java
@@ -16,23 +16,37 @@
 
 package com.android.server.ethernet;
 
+import static com.android.net.module.util.DeviceConfigUtils.TETHERING_MODULE_NAME;
+
 import android.annotation.Nullable;
+import android.content.ApexEnvironment;
 import android.net.IpConfiguration;
 import android.os.Environment;
 import android.util.ArrayMap;
+import android.util.AtomicFile;
+import android.util.Log;
 
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.server.net.IpConfigStore;
 
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
 
 /**
  * This class provides an API to store and manage Ethernet network configuration.
  */
 public class EthernetConfigStore {
-    private static final String ipConfigFile = Environment.getDataDirectory() +
-            "/misc/ethernet/ipconfig.txt";
+    private static final String TAG = EthernetConfigStore.class.getSimpleName();
+    private static final String CONFIG_FILE = "ipconfig.txt";
+    private static final String FILE_PATH = "/misc/ethernet/";
+    private static final String LEGACY_IP_CONFIG_FILE_PATH = Environment.getDataDirectory()
+            + FILE_PATH;
+    private static final String APEX_IP_CONFIG_FILE_PATH = ApexEnvironment.getApexEnvironment(
+            TETHERING_MODULE_NAME).getDeviceProtectedDataDir() + FILE_PATH;
 
     private IpConfigStore mStore = new IpConfigStore();
-    private ArrayMap<String, IpConfiguration> mIpConfigurations;
+    private final ArrayMap<String, IpConfiguration> mIpConfigurations;
     private IpConfiguration mIpConfigurationForDefaultInterface;
     private final Object mSync = new Object();
 
@@ -40,22 +54,70 @@
         mIpConfigurations = new ArrayMap<>(0);
     }
 
-    public void read() {
-        synchronized (mSync) {
-            ArrayMap<String, IpConfiguration> configs =
-                    IpConfigStore.readIpConfigurations(ipConfigFile);
+    private static boolean doesConfigFileExist(final String filepath) {
+        return new File(filepath).exists();
+    }
 
-            // This configuration may exist in old file versions when there was only a single active
-            // Ethernet interface.
-            if (configs.containsKey("0")) {
-                mIpConfigurationForDefaultInterface = configs.remove("0");
+    private void writeLegacyIpConfigToApexPath(final String newFilePath, final String oldFilePath,
+            final String filename) {
+        final File directory = new File(newFilePath);
+        if (!directory.exists()) {
+            directory.mkdirs();
+        }
+
+        // Write the legacy IP config to the apex file path.
+        FileOutputStream fos = null;
+        final AtomicFile dst = new AtomicFile(new File(newFilePath + filename));
+        final AtomicFile src = new AtomicFile(new File(oldFilePath + filename));
+        try {
+            final byte[] raw = src.readFully();
+            if (raw.length > 0) {
+                fos = dst.startWrite();
+                fos.write(raw);
+                fos.flush();
+                dst.finishWrite(fos);
             }
-
-            mIpConfigurations = configs;
+        } catch (IOException e) {
+            Log.e(TAG, "Fail to sync the legacy IP config to the apex file path.");
+            dst.failWrite(fos);
         }
     }
 
+    public void read() {
+        read(APEX_IP_CONFIG_FILE_PATH, LEGACY_IP_CONFIG_FILE_PATH, CONFIG_FILE);
+    }
+
+    @VisibleForTesting
+    void read(final String newFilePath, final String oldFilePath, final String filename) {
+        synchronized (mSync) {
+            // Attempt to read the IP configuration from apex file path first.
+            if (doesConfigFileExist(newFilePath + filename)) {
+                loadConfigFileLocked(newFilePath + filename);
+                return;
+            }
+
+            // If the config file doesn't exist in the apex file path, attempt to read it from
+            // the legacy file path, if config file exists, write the legacy IP configuration to
+            // apex config file path, this should just happen on the first boot. New or updated
+            // config entries are only written to the apex config file later.
+            if (!doesConfigFileExist(oldFilePath + filename)) return;
+            loadConfigFileLocked(oldFilePath + filename);
+            writeLegacyIpConfigToApexPath(newFilePath, oldFilePath, filename);
+        }
+    }
+
+    private void loadConfigFileLocked(final String filepath) {
+        final ArrayMap<String, IpConfiguration> configs =
+                IpConfigStore.readIpConfigurations(filepath);
+        mIpConfigurations.putAll(configs);
+    }
+
     public void write(String iface, IpConfiguration config) {
+        write(iface, config, APEX_IP_CONFIG_FILE_PATH + CONFIG_FILE);
+    }
+
+    @VisibleForTesting
+    void write(String iface, IpConfiguration config, String filepath) {
         boolean modified;
 
         synchronized (mSync) {
@@ -67,7 +129,7 @@
             }
 
             if (modified) {
-                mStore.writeIpConfigurations(ipConfigFile, mIpConfigurations);
+                mStore.writeIpConfigurations(filepath, mIpConfigurations);
             }
         }
     }
@@ -80,9 +142,6 @@
 
     @Nullable
     public IpConfiguration getIpConfigurationForDefaultInterface() {
-        synchronized (mSync) {
-            return mIpConfigurationForDefaultInterface == null
-                    ? null : new IpConfiguration(mIpConfigurationForDefaultInterface);
-        }
+        return null;
     }
 }
diff --git a/service/native/TrafficController.cpp b/service/native/TrafficController.cpp
index 5581c40..a9ede6a 100644
--- a/service/native/TrafficController.cpp
+++ b/service/native/TrafficController.cpp
@@ -184,6 +184,7 @@
     RETURN_IF_NOT_OK(mUidOwnerMap.init(UID_OWNER_MAP_PATH));
     RETURN_IF_NOT_OK(mUidOwnerMap.clear());
     RETURN_IF_NOT_OK(mUidPermissionMap.init(UID_PERMISSION_MAP_PATH));
+    ALOGI("%s successfully", __func__);
 
     return netdutils::status::ok;
 }
diff --git a/service/native/TrafficControllerTest.cpp b/service/native/TrafficControllerTest.cpp
index ad53cb8..3f13532 100644
--- a/service/native/TrafficControllerTest.cpp
+++ b/service/native/TrafficControllerTest.cpp
@@ -685,7 +685,7 @@
                 if (res.ok() || (res.error().code() == ENOENT)) {
                     return Result<void>();
                 }
-                ALOGE("Failed to delete data(cookie = %" PRIu64 "): %s\n", key,
+                ALOGE("Failed to delete data(cookie = %" PRIu64 "): %s", key,
                       strerror(res.error().code()));
             }
             // Move forward to next cookie in the map.
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
index 524bd65..93e9dcd 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
@@ -217,7 +217,10 @@
             Log.d(TAG, "Expecting count " + expectedCount + " but actual is " + count + " after "
                     + attempts + " attempts; sleeping "
                     + SLEEP_TIME_SEC + " seconds before trying again");
-            SystemClock.sleep(SLEEP_TIME_SEC * SECOND_IN_MS);
+            // No sleep after the last turn
+            if (attempts <= maxAttempts) {
+                SystemClock.sleep(SLEEP_TIME_SEC * SECOND_IN_MS);
+            }
         } while (attempts <= maxAttempts);
         assertEquals("Number of expected broadcasts for " + receiverName + " not reached after "
                 + maxAttempts * SLEEP_TIME_SEC + " seconds", expectedCount, count);
@@ -328,7 +331,10 @@
             }
             Log.d(TAG, "App not on background state (" + state + ") on attempt #" + i
                     + "; sleeping 1s before trying again");
-            SystemClock.sleep(SECOND_IN_MS);
+            // No sleep after the last turn
+            if (i < maxTries) {
+                SystemClock.sleep(SECOND_IN_MS);
+            }
         }
         fail("App2 (" + mUid + ") is not on background state after "
                 + maxTries + " attempts: " + state);
@@ -347,7 +353,10 @@
             Log.d(TAG, "App not on foreground state on attempt #" + i
                     + "; sleeping 1s before trying again");
             turnScreenOn();
-            SystemClock.sleep(SECOND_IN_MS);
+            // No sleep after the last turn
+            if (i < maxTries) {
+                SystemClock.sleep(SECOND_IN_MS);
+            }
         }
         fail("App2 (" + mUid + ") is not on foreground state after "
                 + maxTries + " attempts: " + state);
@@ -365,7 +374,10 @@
             }
             Log.d(TAG, "App not on foreground service state on attempt #" + i
                     + "; sleeping 1s before trying again");
-            SystemClock.sleep(SECOND_IN_MS);
+            // No sleep after the last turn
+            if (i < maxTries) {
+                SystemClock.sleep(SECOND_IN_MS);
+            }
         }
         fail("App2 (" + mUid + ") is not on foreground service state after "
                 + maxTries + " attempts: " + state);
@@ -506,7 +518,10 @@
             Log.v(TAG, "Command '" + command + "' returned '" + result + " instead of '"
                     + checker.getExpected() + "' on attempt #" + i
                     + "; sleeping " + napTimeSeconds + "s before trying again");
-            SystemClock.sleep(napTimeSeconds * SECOND_IN_MS);
+            // No sleep after the last turn
+            if (i < maxTries) {
+                SystemClock.sleep(napTimeSeconds * SECOND_IN_MS);
+            }
         }
         fail("Command '" + command + "' did not return '" + checker.getExpected() + "' after "
                 + maxTries
@@ -578,7 +593,10 @@
             }
             Log.v(TAG, list + " check for uid " + uid + " doesn't match yet (expected "
                     + expected + ", got " + actual + "); sleeping 1s before polling again");
-            SystemClock.sleep(SECOND_IN_MS);
+            // No sleep after the last turn
+            if (i < maxTries) {
+                SystemClock.sleep(SECOND_IN_MS);
+            }
         }
         fail(list + " check for uid " + uid + " failed: expected " + expected + ", got " + actual
                 + ". Full list: " + uids);
@@ -738,7 +756,8 @@
 
     protected void assertAppIdle(boolean enabled) throws Exception {
         try {
-            assertDelayedShellCommand("am get-inactive " + TEST_APP2_PKG, 15, 2, "Idle=" + enabled);
+            assertDelayedShellCommand("am get-inactive " + TEST_APP2_PKG,
+                    30 /* maxTries */, 1 /* napTimeSeconds */, "Idle=" + enabled);
         } catch (Throwable e) {
             throw e;
         }
@@ -765,7 +784,10 @@
                 return;
             }
             Log.v(TAG, "app2 receiver is not ready yet; sleeping 1s before polling again");
-            SystemClock.sleep(SECOND_IN_MS);
+            // No sleep after the last turn
+            if (i < maxTries) {
+                SystemClock.sleep(SECOND_IN_MS);
+            }
         }
         fail("app2 receiver is not ready in " + mUid);
     }
@@ -814,8 +836,6 @@
             return;
         } else if (type == TYPE_COMPONENT_ACTIVTIY) {
             turnScreenOn();
-            // Wait for screen-on state to propagate through the system.
-            SystemClock.sleep(2000);
             final CountDownLatch latch = new CountDownLatch(1);
             final Intent launchIntent = getIntentForComponent(type);
             final Bundle extras = new Bundle();
diff --git a/tests/cts/hostside/app2/src/com/android/cts/net/hostside/app2/MyActivity.java b/tests/cts/hostside/app2/src/com/android/cts/net/hostside/app2/MyActivity.java
index 51acfdf..82f13ae 100644
--- a/tests/cts/hostside/app2/src/com/android/cts/net/hostside/app2/MyActivity.java
+++ b/tests/cts/hostside/app2/src/com/android/cts/net/hostside/app2/MyActivity.java
@@ -29,6 +29,7 @@
 import android.os.Bundle;
 import android.os.RemoteException;
 import android.util.Log;
+import android.view.WindowManager;
 
 import androidx.annotation.GuardedBy;
 
@@ -46,6 +47,8 @@
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         Log.d(TAG, "MyActivity.onCreate()");
+
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 
     @Override
diff --git a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
index 8f6786f..3b88189 100644
--- a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
+++ b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
@@ -3235,14 +3235,16 @@
             // TODD: Have a significant signal to know the uids has been sent to netd.
             assertBindSocketToNetworkSuccess(network);
 
-            // Uid is in allowed list. Try file network request again.
-            requestNetwork(restrictedRequest, restrictedNetworkCb);
-            // Verify that the network is restricted.
-            restrictedNetworkCb.eventuallyExpect(CallbackEntry.NETWORK_CAPS_UPDATED,
-                    NETWORK_CALLBACK_TIMEOUT_MS,
-                    entry -> network.equals(entry.getNetwork())
-                            && (!((CallbackEntry.CapabilitiesChanged) entry).getCaps()
-                            .hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)));
+            if (TestUtils.shouldTestTApis()) {
+                // Uid is in allowed list. Try file network request again.
+                requestNetwork(restrictedRequest, restrictedNetworkCb);
+                // Verify that the network is restricted.
+                restrictedNetworkCb.eventuallyExpect(CallbackEntry.NETWORK_CAPS_UPDATED,
+                        NETWORK_CALLBACK_TIMEOUT_MS,
+                        entry -> network.equals(entry.getNetwork())
+                                && (!((CallbackEntry.CapabilitiesChanged) entry).getCaps()
+                                .hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)));
+            }
         } finally {
             agent.unregister();
 
diff --git a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
index 088d202..33a0a83 100644
--- a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
@@ -52,9 +52,7 @@
 import androidx.test.runner.AndroidJUnit4
 import com.android.net.module.util.ArrayTrackRecord
 import com.android.net.module.util.TrackRecord
-import com.android.networkstack.apishim.ConstantsShim
 import com.android.networkstack.apishim.NsdShimImpl
-import com.android.testutils.SC_V2
 import com.android.testutils.TestableNetworkAgent
 import com.android.testutils.TestableNetworkCallback
 import com.android.testutils.runAsShell
@@ -249,9 +247,11 @@
     fun setUp() {
         handlerThread.start()
 
-        runAsShell(MANAGE_TEST_NETWORKS) {
-            testNetwork1 = createTestNetwork()
-            testNetwork2 = createTestNetwork()
+        if (TestUtils.shouldTestTApis()) {
+            runAsShell(MANAGE_TEST_NETWORKS) {
+                testNetwork1 = createTestNetwork()
+                testNetwork2 = createTestNetwork()
+            }
         }
     }
 
@@ -290,9 +290,11 @@
 
     @After
     fun tearDown() {
-        runAsShell(MANAGE_TEST_NETWORKS) {
-            testNetwork1.close(cm)
-            testNetwork2.close(cm)
+        if (TestUtils.shouldTestTApis()) {
+            runAsShell(MANAGE_TEST_NETWORKS) {
+                testNetwork1.close(cm)
+                testNetwork2.close(cm)
+            }
         }
         handlerThread.quitSafely()
     }
@@ -419,7 +421,7 @@
     @Test
     fun testNsdManager_DiscoverOnNetwork() {
         // This test requires shims supporting T+ APIs (discovering on specific network)
-        assumeTrue(ConstantsShim.VERSION > SC_V2)
+        assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
         si.serviceType = SERVICE_TYPE
@@ -453,7 +455,7 @@
     @Test
     fun testNsdManager_DiscoverWithNetworkRequest() {
         // This test requires shims supporting T+ APIs (discovering on network request)
-        assumeTrue(ConstantsShim.VERSION > SC_V2)
+        assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
         si.serviceType = SERVICE_TYPE
@@ -518,7 +520,7 @@
     @Test
     fun testNsdManager_ResolveOnNetwork() {
         // This test requires shims supporting T+ APIs (NsdServiceInfo.network)
-        assumeTrue(ConstantsShim.VERSION > SC_V2)
+        assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
         si.serviceType = SERVICE_TYPE
@@ -562,7 +564,7 @@
     @Test
     fun testNsdManager_RegisterOnNetwork() {
         // This test requires shims supporting T+ APIs (NsdServiceInfo.network)
-        assumeTrue(ConstantsShim.VERSION > SC_V2)
+        assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
         si.serviceType = SERVICE_TYPE
diff --git a/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java b/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
index 45f3d3c..061dc87 100644
--- a/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
+++ b/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
@@ -783,6 +783,23 @@
     }
 
     @Test
+    public void testSetNetworkForTunnelInterfaceFailsForNullLp() throws Exception {
+        final IpSecTunnelInterfaceResponse createTunnelResp =
+                createAndValidateTunnel(mSourceAddr, mDestinationAddr, BLESSED_PACKAGE);
+        final Network newFakeNetwork = new Network(1000);
+        final int tunnelIfaceResourceId = createTunnelResp.resourceId;
+
+        try {
+            mIpSecService.setNetworkForTunnelInterface(
+                    tunnelIfaceResourceId, newFakeNetwork, BLESSED_PACKAGE);
+            fail(
+                    "Expected an IllegalArgumentException for underlying network with null"
+                            + " LinkProperties");
+        } catch (IllegalArgumentException expected) {
+        }
+    }
+
+    @Test
     public void testSetNetworkForTunnelInterfaceFailsForInvalidResourceId() throws Exception {
         final IpSecTunnelInterfaceResponse createTunnelResp =
                 createAndValidateTunnel(mSourceAddr, mDestinationAddr, BLESSED_PACKAGE);
diff --git a/tests/unit/java/com/android/server/ethernet/EthernetConfigStoreTest.java b/tests/unit/java/com/android/server/ethernet/EthernetConfigStoreTest.java
new file mode 100644
index 0000000..a9f80ea
--- /dev/null
+++ b/tests/unit/java/com/android/server/ethernet/EthernetConfigStoreTest.java
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2022 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.ethernet;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import android.content.Context;
+import android.net.InetAddresses;
+import android.net.IpConfiguration;
+import android.net.IpConfiguration.IpAssignment;
+import android.net.IpConfiguration.ProxySettings;
+import android.net.LinkAddress;
+import android.net.ProxyInfo;
+import android.net.StaticIpConfiguration;
+import android.util.ArrayMap;
+
+import androidx.test.InstrumentationRegistry;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.File;
+import java.net.InetAddress;
+import java.util.ArrayList;
+import java.util.List;
+
+@RunWith(AndroidJUnit4.class)
+public class EthernetConfigStoreTest {
+    private static final LinkAddress LINKADDR = new LinkAddress("192.168.1.100/25");
+    private static final InetAddress GATEWAY = InetAddresses.parseNumericAddress("192.168.1.1");
+    private static final InetAddress DNS1 = InetAddresses.parseNumericAddress("8.8.8.8");
+    private static final InetAddress DNS2 = InetAddresses.parseNumericAddress("8.8.4.4");
+    private static final StaticIpConfiguration STATIC_IP_CONFIG =
+            new StaticIpConfiguration.Builder()
+                    .setIpAddress(LINKADDR)
+                    .setGateway(GATEWAY)
+                    .setDnsServers(new ArrayList<InetAddress>(
+                            List.of(DNS1, DNS2)))
+                    .build();
+    private static final ProxyInfo PROXY_INFO = ProxyInfo.buildDirectProxy("test", 8888);
+    private static final IpConfiguration APEX_IP_CONFIG =
+            new IpConfiguration(IpAssignment.DHCP, ProxySettings.NONE, null, null);
+    private static final IpConfiguration LEGACY_IP_CONFIG =
+            new IpConfiguration(IpAssignment.STATIC, ProxySettings.STATIC, STATIC_IP_CONFIG,
+                    PROXY_INFO);
+
+    private EthernetConfigStore mEthernetConfigStore;
+    private File mApexTestDir;
+    private File mLegacyTestDir;
+    private File mApexConfigFile;
+    private File mLegacyConfigFile;
+
+    private void createTestDir() {
+        final Context context = InstrumentationRegistry.getContext();
+        final File baseDir = context.getFilesDir();
+        mApexTestDir = new File(baseDir.getPath() + "/apex");
+        mApexTestDir.mkdirs();
+
+        mLegacyTestDir = new File(baseDir.getPath() + "/legacy");
+        mLegacyTestDir.mkdirs();
+    }
+
+    @Before
+    public void setUp() {
+        createTestDir();
+        mEthernetConfigStore = new EthernetConfigStore();
+    }
+
+    @After
+    public void tearDown() {
+        mApexTestDir.delete();
+        mLegacyTestDir.delete();
+    }
+
+    private void assertConfigFileExist(final String filepath) {
+        assertTrue(new File(filepath).exists());
+    }
+
+    /** Wait for the delayed write operation completes. */
+    private void waitForMs(long ms) {
+        try {
+            Thread.sleep(ms);
+        } catch (final InterruptedException e) {
+            fail("Thread was interrupted");
+        }
+    }
+
+    @Test
+    public void testWriteIpConfigToApexFilePathAndRead() throws Exception {
+        // Write the config file to the apex file path, pretend the config file exits and
+        // check if IP config should be read from apex file path.
+        mApexConfigFile = new File(mApexTestDir.getPath(), "test.txt");
+        mEthernetConfigStore.write("eth0", APEX_IP_CONFIG, mApexConfigFile.getPath());
+        waitForMs(50);
+
+        mEthernetConfigStore.read(mApexTestDir.getPath(), mLegacyTestDir.getPath(), "/test.txt");
+        final ArrayMap<String, IpConfiguration> ipConfigurations =
+                mEthernetConfigStore.getIpConfigurations();
+        assertEquals(APEX_IP_CONFIG, ipConfigurations.get("eth0"));
+
+        mApexConfigFile.delete();
+    }
+
+    @Test
+    public void testWriteIpConfigToLegacyFilePathAndRead() throws Exception {
+        // Write the config file to the legacy file path, pretend the config file exits and
+        // check if IP config should be read from legacy file path.
+        mLegacyConfigFile = new File(mLegacyTestDir, "test.txt");
+        mEthernetConfigStore.write("0", LEGACY_IP_CONFIG, mLegacyConfigFile.getPath());
+        waitForMs(50);
+
+        mEthernetConfigStore.read(mApexTestDir.getPath(), mLegacyTestDir.getPath(), "/test.txt");
+        final ArrayMap<String, IpConfiguration> ipConfigurations =
+                mEthernetConfigStore.getIpConfigurations();
+        assertEquals(LEGACY_IP_CONFIG, ipConfigurations.get("0"));
+
+        // Check the same config file in apex file path is created.
+        assertConfigFileExist(mApexTestDir.getPath() + "/test.txt");
+
+        final File apexConfigFile = new File(mApexTestDir.getPath() + "/test.txt");
+        apexConfigFile.delete();
+        mLegacyConfigFile.delete();
+    }
+}