diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index a5e9f31..1a5299b 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -3695,8 +3695,9 @@
     private static final HashMap<NetworkRequest, NetworkCallback> sCallbacks = new HashMap<>();
     private static CallbackHandler sCallbackHandler;
 
-    private NetworkRequest sendRequestForNetwork(NetworkCapabilities need, NetworkCallback callback,
-            int timeoutMs, NetworkRequest.Type reqType, int legacyType, CallbackHandler handler) {
+    private NetworkRequest sendRequestForNetwork(int asUid, NetworkCapabilities need,
+            NetworkCallback callback, int timeoutMs, NetworkRequest.Type reqType, int legacyType,
+            CallbackHandler handler) {
         printStackTrace();
         checkCallbackNotNull(callback);
         Preconditions.checkArgument(
@@ -3721,8 +3722,8 @@
                             getAttributionTag());
                 } else {
                     request = mService.requestNetwork(
-                            need, reqType.ordinal(), messenger, timeoutMs, binder, legacyType,
-                            callbackFlags, callingPackageName, getAttributionTag());
+                            asUid, need, reqType.ordinal(), messenger, timeoutMs, binder,
+                            legacyType, callbackFlags, callingPackageName, getAttributionTag());
                 }
                 if (request != null) {
                     sCallbacks.put(request, callback);
@@ -3737,6 +3738,12 @@
         return request;
     }
 
+    private NetworkRequest sendRequestForNetwork(NetworkCapabilities need, NetworkCallback callback,
+            int timeoutMs, NetworkRequest.Type reqType, int legacyType, CallbackHandler handler) {
+        return sendRequestForNetwork(Process.INVALID_UID, need, callback, timeoutMs, reqType,
+                legacyType, handler);
+    }
+
     /**
      * Helper function to request a network with a particular legacy type.
      *
@@ -4220,8 +4227,40 @@
     @RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
     public void registerDefaultNetworkCallback(@NonNull NetworkCallback networkCallback,
             @NonNull Handler handler) {
+        registerDefaultNetworkCallbackAsUid(Process.INVALID_UID, networkCallback, handler);
+    }
+
+    /**
+     * Registers to receive notifications about changes in the default network for the specified
+     * UID. This may be a physical network or a virtual network, such as a VPN that applies to the
+     * UID. The callbacks will continue to be called until either the application exits or
+     * {@link #unregisterNetworkCallback(NetworkCallback)} is called.
+     *
+     * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+     * number of outstanding requests to 100 per app (identified by their UID), shared with
+     * all variants of this method, of {@link #requestNetwork} as well as
+     * {@link ConnectivityDiagnosticsManager#registerConnectivityDiagnosticsCallback}.
+     * Requesting a network with this method will count toward this limit. If this limit is
+     * exceeded, an exception will be thrown. To avoid hitting this issue and to conserve resources,
+     * make sure to unregister the callbacks with
+     * {@link #unregisterNetworkCallback(NetworkCallback)}.
+     *
+     * @param uid the UID for which to track default network changes.
+     * @param networkCallback The {@link NetworkCallback} that the system will call as the
+     *                        UID's default network changes.
+     * @param handler {@link Handler} to specify the thread upon which the callback will be invoked.
+     * @throws RuntimeException if the app already has too many callbacks registered.
+     * @hide
+     */
+    // TODO: @SystemApi(client=MODULE_LIBRARIES)
+    @SuppressLint({"ExecutorRegistration", "PairedRegistration"})
+    @RequiresPermission(anyOf = {
+            NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
+            android.Manifest.permission.NETWORK_SETTINGS})
+    public void registerDefaultNetworkCallbackAsUid(int uid,
+            @NonNull NetworkCallback networkCallback, @NonNull Handler handler) {
         CallbackHandler cbHandler = new CallbackHandler(handler);
-        sendRequestForNetwork(null /* NetworkCapabilities need */, networkCallback, 0,
+        sendRequestForNetwork(uid, null /* need */, networkCallback, 0 /* timeoutMs */,
                 TRACK_DEFAULT, TYPE_NONE, cbHandler);
     }
 
diff --git a/framework/src/android/net/IConnectivityManager.aidl b/framework/src/android/net/IConnectivityManager.aidl
index 3300fa8..0826922 100644
--- a/framework/src/android/net/IConnectivityManager.aidl
+++ b/framework/src/android/net/IConnectivityManager.aidl
@@ -142,7 +142,7 @@
             in NetworkCapabilities nc, in NetworkScore score, in NetworkAgentConfig config,
             in int factorySerialNumber);
 
-    NetworkRequest requestNetwork(in NetworkCapabilities networkCapabilities, int reqType,
+    NetworkRequest requestNetwork(int uid, in NetworkCapabilities networkCapabilities, int reqType,
             in Messenger messenger, int timeoutSec, in IBinder binder, int legacy,
             int callbackFlags, String callingPackageName, String callingAttributionTag);
 
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index c040501..a0bdd7f 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -5649,7 +5649,7 @@
     }
 
     @Override
-    public NetworkRequest requestNetwork(NetworkCapabilities networkCapabilities,
+    public NetworkRequest requestNetwork(int asUid, NetworkCapabilities networkCapabilities,
             int reqTypeInt, Messenger messenger, int timeoutMs, IBinder binder,
             int legacyType, int callbackFlags, @NonNull String callingPackageName,
             @Nullable String callingAttributionTag) {
@@ -5661,6 +5661,12 @@
         }
         final NetworkCapabilities defaultNc = mDefaultRequest.mRequests.get(0).networkCapabilities;
         final int callingUid = mDeps.getCallingUid();
+        // Privileged callers can track the default network of another UID by passing in a UID.
+        if (asUid != Process.INVALID_UID) {
+            enforceSettingsPermission();
+        } else {
+            asUid = callingUid;
+        }
         final NetworkRequest.Type reqType;
         try {
             reqType = NetworkRequest.Type.values()[reqTypeInt];
@@ -5670,10 +5676,10 @@
         switch (reqType) {
             case TRACK_DEFAULT:
                 // If the request type is TRACK_DEFAULT, the passed {@code networkCapabilities}
-                // is unused and will be replaced by ones appropriate for the caller.
-                // This allows callers to keep track of the default network for their app.
+                // is unused and will be replaced by ones appropriate for the UID (usually, the
+                // calling app). This allows callers to keep track of the default network.
                 networkCapabilities = copyDefaultNetworkCapabilitiesForUid(
-                        defaultNc, callingUid, callingUid, callingPackageName);
+                        defaultNc, asUid, callingUid, callingPackageName);
                 enforceAccessPermission();
                 break;
             case TRACK_SYSTEM_DEFAULT:
@@ -5725,7 +5731,7 @@
         final NetworkRequest networkRequest = new NetworkRequest(networkCapabilities, legacyType,
                 nextNetworkRequestId(), reqType);
         final NetworkRequestInfo nri = getNriToRegister(
-                callingUid, networkRequest, messenger, binder, callbackFlags,
+                asUid, networkRequest, messenger, binder, callbackFlags,
                 callingAttributionTag);
         if (DBG) log("requestNetwork for " + nri);
 
@@ -9574,7 +9580,7 @@
                     callbackRequest,
                     copyNetworkRequestsForUid(
                             trackingNri.mRequests, callbackRequest.mAsUid,
-                            request.getRequestorUid(), request.getRequestorPackageName())));
+                            callbackRequest.mUid, request.getRequestorPackageName())));
         }
         return callbackRequestsToRegister;
     }
diff --git a/tests/net/java/android/net/ConnectivityManagerTest.java b/tests/net/java/android/net/ConnectivityManagerTest.java
index 6fc605e..36f205b 100644
--- a/tests/net/java/android/net/ConnectivityManagerTest.java
+++ b/tests/net/java/android/net/ConnectivityManagerTest.java
@@ -64,6 +64,7 @@
 import android.os.Looper;
 import android.os.Message;
 import android.os.Messenger;
+import android.os.Process;
 
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
@@ -219,8 +220,8 @@
         ArgumentCaptor<Messenger> captor = ArgumentCaptor.forClass(Messenger.class);
 
         // register callback
-        when(mService.requestNetwork(any(), anyInt(), captor.capture(), anyInt(), any(), anyInt(),
-                anyInt(), any(), nullable(String.class))).thenReturn(request);
+        when(mService.requestNetwork(anyInt(), any(), anyInt(), captor.capture(), anyInt(), any(),
+                anyInt(), anyInt(), any(), nullable(String.class))).thenReturn(request);
         manager.requestNetwork(request, callback, handler);
 
         // callback triggers
@@ -247,8 +248,8 @@
         ArgumentCaptor<Messenger> captor = ArgumentCaptor.forClass(Messenger.class);
 
         // register callback
-        when(mService.requestNetwork(any(), anyInt(), captor.capture(), anyInt(), any(), anyInt(),
-                anyInt(), any(), nullable(String.class))).thenReturn(req1);
+        when(mService.requestNetwork(anyInt(), any(), anyInt(), captor.capture(), anyInt(), any(),
+                anyInt(), anyInt(), any(), nullable(String.class))).thenReturn(req1);
         manager.requestNetwork(req1, callback, handler);
 
         // callback triggers
@@ -265,8 +266,8 @@
         verify(callback, timeout(100).times(0)).onLosing(any(), anyInt());
 
         // callback can be registered again
-        when(mService.requestNetwork(any(), anyInt(), captor.capture(), anyInt(), any(), anyInt(),
-                anyInt(), any(), nullable(String.class))).thenReturn(req2);
+        when(mService.requestNetwork(anyInt(), any(), anyInt(), captor.capture(), anyInt(), any(),
+                anyInt(), anyInt(), any(), nullable(String.class))).thenReturn(req2);
         manager.requestNetwork(req2, callback, handler);
 
         // callback triggers
@@ -289,8 +290,8 @@
         info.targetSdkVersion = VERSION_CODES.N_MR1 + 1;
 
         when(mCtx.getApplicationInfo()).thenReturn(info);
-        when(mService.requestNetwork(any(), anyInt(), any(), anyInt(), any(), anyInt(), anyInt(),
-                any(), nullable(String.class))).thenReturn(request);
+        when(mService.requestNetwork(anyInt(), any(), anyInt(), any(), anyInt(), any(), anyInt(),
+                anyInt(), any(), nullable(String.class))).thenReturn(request);
 
         Handler handler = new Handler(Looper.getMainLooper());
         manager.requestNetwork(request, callback, handler);
@@ -357,34 +358,40 @@
         final NetworkCallback callback = new ConnectivityManager.NetworkCallback();
 
         manager.requestNetwork(request, callback);
-        verify(mService).requestNetwork(eq(request.networkCapabilities),
+        verify(mService).requestNetwork(eq(Process.INVALID_UID), eq(request.networkCapabilities),
                 eq(REQUEST.ordinal()), any(), anyInt(), any(), eq(TYPE_NONE), anyInt(),
                 eq(testPkgName), eq(testAttributionTag));
         reset(mService);
 
         // Verify that register network callback does not calls requestNetwork at all.
         manager.registerNetworkCallback(request, callback);
-        verify(mService, never()).requestNetwork(any(), anyInt(), any(), anyInt(), any(), anyInt(),
-                anyInt(), any(), any());
+        verify(mService, never()).requestNetwork(anyInt(), any(), anyInt(), any(), anyInt(), any(),
+                anyInt(), anyInt(), any(), any());
         verify(mService).listenForNetwork(eq(request.networkCapabilities), any(), any(), anyInt(),
                 eq(testPkgName), eq(testAttributionTag));
         reset(mService);
 
+        Handler handler = new Handler(ConnectivityThread.getInstanceLooper());
+
         manager.registerDefaultNetworkCallback(callback);
-        verify(mService).requestNetwork(eq(null),
+        verify(mService).requestNetwork(eq(Process.INVALID_UID), eq(null),
                 eq(TRACK_DEFAULT.ordinal()), any(), anyInt(), any(), eq(TYPE_NONE), anyInt(),
                 eq(testPkgName), eq(testAttributionTag));
         reset(mService);
 
-        Handler handler = new Handler(ConnectivityThread.getInstanceLooper());
+        manager.registerDefaultNetworkCallbackAsUid(42, callback, handler);
+        verify(mService).requestNetwork(eq(42), eq(null),
+                eq(TRACK_DEFAULT.ordinal()), any(), anyInt(), any(), eq(TYPE_NONE), anyInt(),
+                eq(testPkgName), eq(testAttributionTag));
+
         manager.requestBackgroundNetwork(request, handler, callback);
-        verify(mService).requestNetwork(eq(request.networkCapabilities),
+        verify(mService).requestNetwork(eq(Process.INVALID_UID), eq(request.networkCapabilities),
                 eq(BACKGROUND_REQUEST.ordinal()), any(), anyInt(), any(), eq(TYPE_NONE), anyInt(),
                 eq(testPkgName), eq(testAttributionTag));
         reset(mService);
 
         manager.registerSystemDefaultNetworkCallback(callback, handler);
-        verify(mService).requestNetwork(eq(null),
+        verify(mService).requestNetwork(eq(Process.INVALID_UID), eq(null),
                 eq(TRACK_SYSTEM_DEFAULT.ordinal()), any(), anyInt(), any(), eq(TYPE_NONE), anyInt(),
                 eq(testPkgName), eq(testAttributionTag));
         reset(mService);
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index ed9a44b..ee17d75 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -1451,6 +1451,23 @@
         });
     }
 
+    private interface ExceptionalRunnable {
+        void run() throws Exception;
+    }
+
+    private void withPermission(String permission, ExceptionalRunnable r) throws Exception {
+        if (mServiceContext.checkCallingOrSelfPermission(permission) == PERMISSION_GRANTED) {
+            r.run();
+            return;
+        }
+        try {
+            mServiceContext.setPermission(permission, PERMISSION_GRANTED);
+            r.run();
+        } finally {
+            mServiceContext.setPermission(permission, PERMISSION_DENIED);
+        }
+    }
+
     private static final int PRIMARY_USER = 0;
     private static final UidRange PRIMARY_UIDRANGE =
             UidRange.createForUser(UserHandle.of(PRIMARY_USER));
@@ -3813,8 +3830,9 @@
             NetworkCapabilities networkCapabilities = new NetworkCapabilities();
             networkCapabilities.addTransportType(TRANSPORT_WIFI)
                     .setNetworkSpecifier(new MatchAllNetworkSpecifier());
-            mService.requestNetwork(networkCapabilities, NetworkRequest.Type.REQUEST.ordinal(),
-                    null, 0, null, ConnectivityManager.TYPE_WIFI, NetworkCallback.FLAG_NONE,
+            mService.requestNetwork(Process.INVALID_UID, networkCapabilities,
+                    NetworkRequest.Type.REQUEST.ordinal(), null, 0, null,
+                    ConnectivityManager.TYPE_WIFI, NetworkCallback.FLAG_NONE,
                     mContext.getPackageName(), getAttributionTag());
         });
 
@@ -4043,7 +4061,7 @@
     }
 
     @Test
-    public void testRegisterSystemDefaultCallbackRequiresNetworkSettings() throws Exception {
+    public void testRegisterPrivilegedDefaultCallbacksRequireNetworkSettings() throws Exception {
         mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR);
         mCellNetworkAgent.connect(false /* validated */);
 
@@ -4052,12 +4070,19 @@
         assertThrows(SecurityException.class,
                 () -> mCm.registerSystemDefaultNetworkCallback(callback, handler));
         callback.assertNoCallback();
+        assertThrows(SecurityException.class,
+                () -> mCm.registerDefaultNetworkCallbackAsUid(APP1_UID, callback, handler));
+        callback.assertNoCallback();
 
         mServiceContext.setPermission(Manifest.permission.NETWORK_SETTINGS,
                 PERMISSION_GRANTED);
         mCm.registerSystemDefaultNetworkCallback(callback, handler);
         callback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
         mCm.unregisterNetworkCallback(callback);
+
+        mCm.registerDefaultNetworkCallbackAsUid(APP1_UID, callback, handler);
+        callback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
+        mCm.unregisterNetworkCallback(callback);
     }
 
     private void setCaptivePortalMode(int mode) {
@@ -7490,6 +7515,10 @@
         final TestNetworkCallback vpnUidDefaultCallback = new TestNetworkCallback();
         registerDefaultNetworkCallbackAsUid(vpnUidDefaultCallback, VPN_UID);
 
+        final TestNetworkCallback vpnDefaultCallbackAsUid = new TestNetworkCallback();
+        mCm.registerDefaultNetworkCallbackAsUid(VPN_UID, vpnDefaultCallbackAsUid,
+                new Handler(ConnectivityThread.getInstanceLooper()));
+
         final int uid = Process.myUid();
         final int userId = UserHandle.getUserId(uid);
         final ArrayList<String> allowList = new ArrayList<>();
@@ -7509,6 +7538,7 @@
         defaultCallback.expectAvailableCallbacksUnvalidatedAndBlocked(mWiFiNetworkAgent);
         vpnUidCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         vpnUidDefaultCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
+        vpnDefaultCallbackAsUid.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertNull(mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
@@ -7522,6 +7552,7 @@
         defaultCallback.expectBlockedStatusCallback(false, mWiFiNetworkAgent);
         vpnUidCallback.assertNoCallback();
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
         expectNetworkRejectNonSecureVpn(inOrder, false, firstHalf, secondHalf);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
@@ -7537,6 +7568,7 @@
         defaultCallback.assertNoCallback();
         vpnUidCallback.assertNoCallback();
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
 
         // The following requires that the UID of this test package is greater than VPN_UID. This
         // is always true in practice because a plain AOSP build with no apps installed has almost
@@ -7558,6 +7590,7 @@
         defaultCallback.assertNoCallback();
         vpnUidCallback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7579,6 +7612,7 @@
         assertBlockedCallbackInAnyOrder(callback, true, mWiFiNetworkAgent, mCellNetworkAgent);
         vpnUidCallback.assertNoCallback();
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertNull(mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
@@ -7591,6 +7625,7 @@
         assertBlockedCallbackInAnyOrder(callback, false, mWiFiNetworkAgent, mCellNetworkAgent);
         vpnUidCallback.assertNoCallback();
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7606,6 +7641,7 @@
         defaultCallback.assertNoCallback();
         vpnUidCallback.assertNoCallback();
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7618,6 +7654,7 @@
         defaultCallback.assertNoCallback();
         vpnUidCallback.assertNoCallback();
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7631,6 +7668,7 @@
         assertBlockedCallbackInAnyOrder(callback, true, mWiFiNetworkAgent, mCellNetworkAgent);
         vpnUidCallback.assertNoCallback();
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertNull(mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
@@ -7642,6 +7680,7 @@
         defaultCallback.expectAvailableThenValidatedCallbacks(mMockVpn);
         vpnUidCallback.assertNoCallback();  // vpnUidCallback has NOT_VPN capability.
         vpnUidDefaultCallback.assertNoCallback();  // VPN does not apply to VPN_UID
+        vpnDefaultCallbackAsUid.assertNoCallback();
         assertEquals(mMockVpn.getNetwork(), mCm.getActiveNetwork());
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7654,12 +7693,14 @@
         defaultCallback.expectAvailableCallbacksUnvalidatedAndBlocked(mWiFiNetworkAgent);
         vpnUidCallback.assertNoCallback();
         vpnUidDefaultCallback.assertNoCallback();
+        vpnDefaultCallbackAsUid.assertNoCallback();
         assertNull(mCm.getActiveNetwork());
 
         mCm.unregisterNetworkCallback(callback);
         mCm.unregisterNetworkCallback(defaultCallback);
         mCm.unregisterNetworkCallback(vpnUidCallback);
         mCm.unregisterNetworkCallback(vpnUidDefaultCallback);
+        mCm.unregisterNetworkCallback(vpnDefaultCallbackAsUid);
     }
 
     private void setupLegacyLockdownVpn() {
@@ -9805,8 +9846,8 @@
         for (int reqTypeInt : invalidReqTypeInts) {
             assertThrows("Expect throws for invalid request type " + reqTypeInt,
                     IllegalArgumentException.class,
-                    () -> mService.requestNetwork(nc, reqTypeInt, null, 0, null,
-                            ConnectivityManager.TYPE_NONE, NetworkCallback.FLAG_NONE,
+                    () -> mService.requestNetwork(Process.INVALID_UID, nc, reqTypeInt, null, 0,
+                            null, ConnectivityManager.TYPE_NONE, NetworkCallback.FLAG_NONE,
                             mContext.getPackageName(), getAttributionTag())
             );
         }
@@ -10377,6 +10418,7 @@
         mCm.registerDefaultNetworkCallback(mDefaultNetworkCallback);
         registerDefaultNetworkCallbackAsUid(mProfileDefaultNetworkCallback,
                 TEST_WORK_PROFILE_APP_UID);
+        // TODO: test using ConnectivityManager#registerDefaultNetworkCallbackAsUid as well.
         mServiceContext.setPermission(
                 Manifest.permission.NETWORK_SETTINGS, PERMISSION_DENIED);
     }
@@ -10396,7 +10438,7 @@
     private void setupMultipleDefaultNetworksForOemNetworkPreferenceNotCurrentUidTest(
             @OemNetworkPreferences.OemNetworkPreference final int networkPrefToSetup)
             throws Exception {
-        final int testPackageNameUid = 123;
+        final int testPackageNameUid = TEST_PACKAGE_UID;
         final String testPackageName = "per.app.defaults.package";
         setupMultipleDefaultNetworksForOemNetworkPreferenceTest(
                 networkPrefToSetup, testPackageNameUid, testPackageName);
@@ -10532,6 +10574,11 @@
         mCm.registerDefaultNetworkCallback(defaultNetworkCallback);
         defaultNetworkCallback.assertNoCallback();
 
+        final TestNetworkCallback otherUidDefaultCallback = new TestNetworkCallback();
+        withPermission(Manifest.permission.NETWORK_SETTINGS, () ->
+                mCm.registerDefaultNetworkCallbackAsUid(TEST_PACKAGE_UID, otherUidDefaultCallback,
+                        new Handler(ConnectivityThread.getInstanceLooper())));
+
         // Setup the test process to use networkPref for their default network.
         setupMultipleDefaultNetworksForOemNetworkPreferenceCurrentUidTest(networkPref);
 
@@ -10542,19 +10589,22 @@
                 null,
                 mEthernetNetworkAgent.getNetwork());
 
-        // At this point with a restricted network used, the available callback should trigger
+        // At this point with a restricted network used, the available callback should trigger.
         defaultNetworkCallback.expectAvailableThenValidatedCallbacks(mEthernetNetworkAgent);
         assertEquals(defaultNetworkCallback.getLastAvailableNetwork(),
                 mEthernetNetworkAgent.getNetwork());
+        otherUidDefaultCallback.assertNoCallback();
 
         // Now bring down the default network which should trigger a LOST callback.
         setOemNetworkPreferenceAgentConnected(TRANSPORT_ETHERNET, false);
 
         // At this point, with no network is available, the lost callback should trigger
         defaultNetworkCallback.expectCallback(CallbackEntry.LOST, mEthernetNetworkAgent);
+        otherUidDefaultCallback.assertNoCallback();
 
         // Confirm we can unregister without issues.
         mCm.unregisterNetworkCallback(defaultNetworkCallback);
+        mCm.unregisterNetworkCallback(otherUidDefaultCallback);
     }
 
     @Test
@@ -10572,6 +10622,11 @@
         mCm.registerDefaultNetworkCallback(defaultNetworkCallback);
         defaultNetworkCallback.assertNoCallback();
 
+        final TestNetworkCallback otherUidDefaultCallback = new TestNetworkCallback();
+        withPermission(Manifest.permission.NETWORK_SETTINGS, () ->
+                mCm.registerDefaultNetworkCallbackAsUid(TEST_PACKAGE_UID, otherUidDefaultCallback,
+                        new Handler(ConnectivityThread.getInstanceLooper())));
+
         // Bring up ethernet with OEM_PAID. This will satisfy NET_CAPABILITY_OEM_PAID.
         // The active nai for the default is null at this point as this is a restricted network.
         setOemNetworkPreferenceAgentConnected(TRANSPORT_ETHERNET, true);
@@ -10583,15 +10638,19 @@
         defaultNetworkCallback.expectAvailableThenValidatedCallbacks(mEthernetNetworkAgent);
         assertEquals(defaultNetworkCallback.getLastAvailableNetwork(),
                 mEthernetNetworkAgent.getNetwork());
+        otherUidDefaultCallback.assertNoCallback();
 
         // Now bring down the default network which should trigger a LOST callback.
         setOemNetworkPreferenceAgentConnected(TRANSPORT_ETHERNET, false);
+        otherUidDefaultCallback.assertNoCallback();
 
         // At this point, with no network is available, the lost callback should trigger
         defaultNetworkCallback.expectCallback(CallbackEntry.LOST, mEthernetNetworkAgent);
+        otherUidDefaultCallback.assertNoCallback();
 
         // Confirm we can unregister without issues.
         mCm.unregisterNetworkCallback(defaultNetworkCallback);
+        mCm.unregisterNetworkCallback(otherUidDefaultCallback);
     }
 
     @Test
@@ -10605,6 +10664,11 @@
         mCm.registerDefaultNetworkCallback(defaultNetworkCallback);
         defaultNetworkCallback.assertNoCallback();
 
+        final TestNetworkCallback otherUidDefaultCallback = new TestNetworkCallback();
+        withPermission(Manifest.permission.NETWORK_SETTINGS, () ->
+                mCm.registerDefaultNetworkCallbackAsUid(TEST_PACKAGE_UID, otherUidDefaultCallback,
+                        new Handler(ConnectivityThread.getInstanceLooper())));
+
         // Setup a process different than the test process to use the default network. This means
         // that the defaultNetworkCallback won't be tracked by the per-app policy.
         setupMultipleDefaultNetworksForOemNetworkPreferenceNotCurrentUidTest(networkPref);
@@ -10620,6 +10684,9 @@
         defaultNetworkCallback.assertNoCallback();
         assertDefaultNetworkCapabilities(userId /* no networks */);
 
+        // The other UID does have access, and gets a callback.
+        otherUidDefaultCallback.expectAvailableThenValidatedCallbacks(mEthernetNetworkAgent);
+
         // Bring up unrestricted cellular. This should now satisfy the default network.
         setOemNetworkPreferenceAgentConnected(TRANSPORT_CELLULAR, true);
         verifyMultipleDefaultNetworksTracksCorrectly(expectedOemPrefRequestSize,
@@ -10627,25 +10694,31 @@
                 mEthernetNetworkAgent.getNetwork());
 
         // At this point with an unrestricted network used, the available callback should trigger
+        // The other UID is unaffected and remains on the paid network.
         defaultNetworkCallback.expectAvailableThenValidatedCallbacks(mCellNetworkAgent);
         assertEquals(defaultNetworkCallback.getLastAvailableNetwork(),
                 mCellNetworkAgent.getNetwork());
         assertDefaultNetworkCapabilities(userId, mCellNetworkAgent);
+        otherUidDefaultCallback.assertNoCallback();
 
         // Now bring down the per-app network.
         setOemNetworkPreferenceAgentConnected(TRANSPORT_ETHERNET, false);
 
-        // Since the callback didn't use the per-app network, no callback should fire.
+        // Since the callback didn't use the per-app network, only the other UID gets a callback.
+        // Because the preference specifies no fallback, it does not switch to cellular.
         defaultNetworkCallback.assertNoCallback();
+        otherUidDefaultCallback.expectCallback(CallbackEntry.LOST, mEthernetNetworkAgent);
 
         // Now bring down the default network.
         setOemNetworkPreferenceAgentConnected(TRANSPORT_CELLULAR, false);
 
         // As this callback was tracking the default, this should now trigger.
         defaultNetworkCallback.expectCallback(CallbackEntry.LOST, mCellNetworkAgent);
+        otherUidDefaultCallback.assertNoCallback();
 
         // Confirm we can unregister without issues.
         mCm.unregisterNetworkCallback(defaultNetworkCallback);
+        mCm.unregisterNetworkCallback(otherUidDefaultCallback);
     }
 
     /**