diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 9e88890..222f5c8 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -87,9 +87,12 @@
 import static android.net.shared.NetworkMonitorUtils.isPrivateDnsValidationRequired;
 import static android.os.Process.INVALID_UID;
 import static android.os.Process.VPN_UID;
+import static android.provider.DeviceConfig.NAMESPACE_CONNECTIVITY;
 import static android.system.OsConstants.IPPROTO_TCP;
 import static android.system.OsConstants.IPPROTO_UDP;
 
+import static com.android.net.module.util.DeviceConfigUtils.TETHERING_MODULE_NAME;
+
 import static java.util.Map.Entry;
 
 import android.Manifest;
@@ -232,6 +235,7 @@
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.BaseNetdUnsolicitedEventListener;
 import com.android.net.module.util.CollectionUtils;
+import com.android.net.module.util.DeviceConfigUtils;
 import com.android.net.module.util.LinkPropertiesUtils.CompareOrUpdateResult;
 import com.android.net.module.util.LinkPropertiesUtils.CompareResult;
 import com.android.net.module.util.LocationPermissionChecker;
@@ -239,6 +243,7 @@
 import com.android.net.module.util.PermissionUtils;
 import com.android.net.module.util.netlink.InetDiagMessage;
 import com.android.server.connectivity.AutodestructReference;
+import com.android.server.connectivity.ConnectivityFlags;
 import com.android.server.connectivity.DnsManager;
 import com.android.server.connectivity.DnsManager.PrivateDnsValidationUpdate;
 import com.android.server.connectivity.FullScore;
@@ -371,6 +376,7 @@
     // The Context is created for UserHandle.ALL.
     private final Context mUserAllContext;
     private final Dependencies mDeps;
+    private final ConnectivityFlags mFlags;
     // 0 is full bad, 100 is full good
     private int mDefaultInetConditionPublished = 0;
 
@@ -1309,6 +1315,14 @@
         public LocationPermissionChecker makeLocationPermissionChecker(Context context) {
             return new LocationPermissionChecker(context);
         }
+
+        /**
+         * @see DeviceConfigUtils#isFeatureEnabled
+         */
+        public boolean isFeatureEnabled(Context context, String name, boolean defaultEnabled) {
+            return DeviceConfigUtils.isFeatureEnabled(context, NAMESPACE_CONNECTIVITY, name,
+                    TETHERING_MODULE_NAME, defaultEnabled);
+        }
     }
 
     public ConnectivityService(Context context) {
@@ -1323,6 +1337,7 @@
         if (DBG) log("ConnectivityService starting up");
 
         mDeps = Objects.requireNonNull(deps, "missing Dependencies");
+        mFlags = new ConnectivityFlags();
         mSystemProperties = mDeps.getSystemProperties();
         mNetIdManager = mDeps.makeNetIdManager();
         mContext = Objects.requireNonNull(context, "missing Context");
@@ -2790,6 +2805,9 @@
      */
     @VisibleForTesting
     public void systemReadyInternal() {
+        // Load flags after PackageManager is ready to query module version
+        mFlags.loadFlags(mDeps, mContext);
+
         // Since mApps in PermissionMonitor needs to be populated first to ensure that
         // listening network request which is sent by MultipathPolicyTracker won't be added
         // NET_CAPABILITY_FOREGROUND capability. Thus, MultipathPolicyTracker.start() must
@@ -4101,7 +4119,11 @@
             }
         }
 
-        rematchAllNetworksAndRequests();
+        if (mFlags.noRematchAllRequestsOnRegister()) {
+            rematchNetworksAndRequests(nris);
+        } else {
+            rematchAllNetworksAndRequests();
+        }
 
         // Requests that have not been matched to a network will not have been sent to the
         // providers, because the old satisfier and the new satisfier are the same (null in this
diff --git a/service/src/com/android/server/connectivity/ConnectivityFlags.java b/service/src/com/android/server/connectivity/ConnectivityFlags.java
new file mode 100644
index 0000000..122ea1c
--- /dev/null
+++ b/service/src/com/android/server/connectivity/ConnectivityFlags.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2021 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.connectivity;
+
+import android.content.Context;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.ConnectivityService;
+
+/**
+ * Collection of constants for the connectivity module.
+ */
+public final class ConnectivityFlags {
+    /**
+     * Minimum module version at which to avoid rematching all requests when a network request is
+     * registered, and rematch only the registered requests instead.
+     */
+    @VisibleForTesting
+    public static final String NO_REMATCH_ALL_REQUESTS_ON_REGISTER =
+            "no_rematch_all_requests_on_register";
+
+    private boolean mNoRematchAllRequestsOnRegister;
+
+    /**
+     * Whether ConnectivityService should avoid avoid rematching all requests when a network
+     * request is registered, and rematch only the registered requests instead.
+     *
+     * This flag is disabled by default.
+     *
+     * IMPORTANT NOTE: This flag is false by default and will only be loaded in ConnectivityService
+     * systemReady. It is also not volatile for performance reasons, so for most threads it may
+     * only change to true after some time. This is fine for this particular flag because it only
+     * controls whether all requests or a subset of requests should be rematched, which is only
+     * a performance optimization, so its value does not need to be consistent over time; but most
+     * flags will not have these properties and should not use the same model.
+     *
+     * TODO: when adding other flags, consider the appropriate timing to load them, and necessary
+     * threading guarantees according to the semantics of the flags.
+     */
+    public boolean noRematchAllRequestsOnRegister() {
+        return mNoRematchAllRequestsOnRegister;
+    }
+
+    /**
+     * Load flag values. Should only be called once, and can only be called once PackageManager is
+     * ready.
+     */
+    public void loadFlags(ConnectivityService.Dependencies deps, Context ctx) {
+        mNoRematchAllRequestsOnRegister = deps.isFeatureEnabled(
+                ctx, NO_REMATCH_ALL_REQUESTS_ON_REGISTER, false /* defaultEnabled */);
+    }
+}