diff --git a/service/ServiceConnectivityResources/res/values/config.xml b/service/ServiceConnectivityResources/res/values/config.xml
index faa9998..1af00c7 100644
--- a/service/ServiceConnectivityResources/res/values/config.xml
+++ b/service/ServiceConnectivityResources/res/values/config.xml
@@ -168,4 +168,15 @@
 
     <!-- Regex of wired ethernet ifaces -->
     <string translatable="false" name="config_ethernet_iface_regex">eth\\d</string>
+
+    <!-- Ignores Wi-Fi validation failures after roam.
+    If validation fails on a Wi-Fi network after a roam to a new BSSID,
+    assume that the roam temporarily disrupted network connectivity, and
+    ignore all failures until this time has passed.
+    NetworkMonitor will continue to attempt validation, and if it fails after this time has passed,
+    the network will be marked unvalidated.
+
+    Only supported up to S. On T+, the Wi-Fi code should use destroyAndAwaitReplacement in order
+    to ensure that apps see the network disconnect and reconnect. -->
+    <integer translatable="false" name="config_validationFailureAfterRoamIgnoreTimeMillis">-1</integer>
 </resources>
diff --git a/service/ServiceConnectivityResources/res/values/overlayable.xml b/service/ServiceConnectivityResources/res/values/overlayable.xml
index 9fa6a30..b92dd08 100644
--- a/service/ServiceConnectivityResources/res/values/overlayable.xml
+++ b/service/ServiceConnectivityResources/res/values/overlayable.xml
@@ -40,6 +40,7 @@
             <item type="string" name="config_ethernet_tcp_buffers"/>
             <item type="array" name="config_ethernet_interfaces"/>
             <item type="string" name="config_ethernet_iface_regex"/>
+            <item type="integer" name="config_validationFailureAfterRoamIgnoreTimeMillis" />
         </policy>
     </overlayable>
 </resources>
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 221b65d..d647664 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -199,6 +199,7 @@
 import android.net.resolv.aidl.PrivateDnsValidationEventParcel;
 import android.net.shared.PrivateDnsConfig;
 import android.net.util.MultinetworkPolicyTracker;
+import android.net.wifi.WifiInfo;
 import android.os.BatteryStatsManager;
 import android.os.Binder;
 import android.os.Build;
@@ -348,6 +349,9 @@
     private static final int DEFAULT_LINGER_DELAY_MS = 30_000;
     private static final int DEFAULT_NASCENT_DELAY_MS = 5_000;
 
+    // The maximum value for the blocking validation result, in milliseconds.
+    public static final int MAX_VALIDATION_FAILURE_BLOCKING_TIME_MS = 10000;
+
     // The maximum number of network request allowed per uid before an exception is thrown.
     @VisibleForTesting
     static final int MAX_NETWORK_REQUESTS_PER_UID = 100;
@@ -3543,6 +3547,7 @@
                 case NetworkAgent.EVENT_NETWORK_CAPABILITIES_CHANGED: {
                     final NetworkCapabilities networkCapabilities = new NetworkCapabilities(
                             (NetworkCapabilities) arg.second);
+                    maybeUpdateWifiRoamTimestamp(nai, networkCapabilities);
                     processCapabilitiesFromAgent(nai, networkCapabilities);
                     updateCapabilities(nai.getCurrentScore(), nai, networkCapabilities);
                     break;
@@ -3790,15 +3795,22 @@
 
         private void handleNetworkTested(
                 @NonNull NetworkAgentInfo nai, int testResult, @NonNull String redirectUrl) {
+            final boolean valid = ((testResult & NETWORK_VALIDATION_RESULT_VALID) != 0);
+            if (!valid && shouldIgnoreValidationFailureAfterRoam(nai)) {
+                // Assume the validation failure is due to a temporary failure after roaming
+                // and ignore it. NetworkMonitor will continue to retry validation. If it
+                // continues to fail after the block timeout expires, the network will be
+                // marked unvalidated. If it succeeds, then validation state will not change.
+                return;
+            }
+
+            final boolean wasValidated = nai.lastValidated;
+            final boolean wasDefault = isDefaultNetwork(nai);
             final boolean wasPartial = nai.partialConnectivity;
             nai.partialConnectivity = ((testResult & NETWORK_VALIDATION_RESULT_PARTIAL) != 0);
             final boolean partialConnectivityChanged =
                     (wasPartial != nai.partialConnectivity);
 
-            final boolean valid = ((testResult & NETWORK_VALIDATION_RESULT_VALID) != 0);
-            final boolean wasValidated = nai.lastValidated;
-            final boolean wasDefault = isDefaultNetwork(nai);
-
             if (DBG) {
                 final String logMsg = !TextUtils.isEmpty(redirectUrl)
                         ? " with redirect to " + redirectUrl
@@ -4197,6 +4209,23 @@
         return nai.created && !nai.destroyed;
     }
 
+    private boolean shouldIgnoreValidationFailureAfterRoam(NetworkAgentInfo nai) {
+        // T+ devices should use destroyAndAwaitReplacement.
+        if (SdkLevel.isAtLeastT()) return false;
+        final long blockTimeOut = Long.valueOf(mResources.get().getInteger(
+                R.integer.config_validationFailureAfterRoamIgnoreTimeMillis));
+        if (blockTimeOut <= MAX_VALIDATION_FAILURE_BLOCKING_TIME_MS
+                && blockTimeOut >= 0) {
+            final long currentTimeMs  = SystemClock.elapsedRealtime();
+            long timeSinceLastRoam = currentTimeMs - nai.lastRoamTimestamp;
+            if (timeSinceLastRoam <= blockTimeOut) {
+                log ("blocked because only " + timeSinceLastRoam + "ms after roam");
+                return true;
+            }
+        }
+        return false;
+    }
+
     private void handleNetworkAgentDisconnected(Message msg) {
         NetworkAgentInfo nai = (NetworkAgentInfo) msg.obj;
         disconnectAndDestroyNetwork(nai);
@@ -9613,6 +9642,18 @@
         return ((VpnTransportInfo) ti).getType();
     }
 
+    private void maybeUpdateWifiRoamTimestamp(NetworkAgentInfo nai, NetworkCapabilities nc) {
+        if (nai == null) return;
+        final TransportInfo prevInfo = nai.networkCapabilities.getTransportInfo();
+        final TransportInfo newInfo = nc.getTransportInfo();
+        if (!(prevInfo instanceof WifiInfo) || !(newInfo instanceof WifiInfo)) {
+            return;
+        }
+        if (!TextUtils.equals(((WifiInfo)prevInfo).getBSSID(), ((WifiInfo)newInfo).getBSSID())) {
+            nai.lastRoamTimestamp = SystemClock.elapsedRealtime();
+        }
+    }
+
     /**
      * @param connectionInfo the connection to resolve.
      * @return {@code uid} if the connection is found and the app has permission to observe it
diff --git a/service/src/com/android/server/connectivity/NetworkAgentInfo.java b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
index cbfc4f7..b73e2cc 100644
--- a/service/src/com/android/server/connectivity/NetworkAgentInfo.java
+++ b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
@@ -192,6 +192,8 @@
     public boolean everConnected;
     // Whether this network has been destroyed and is being kept temporarily until it is replaced.
     public boolean destroyed;
+    // To check how long it has been since last roam.
+    public long lastRoamTimestamp;
 
     // Set to true if this Network successfully passed validation or if it did not satisfy the
     // default NetworkRequest in which case validation will not be attempted.
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index 6d802af..6eec2eb 100644
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -160,6 +160,7 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeTrue;
+import static org.junit.Assume.assumeFalse;
 import static org.mockito.AdditionalMatchers.aryEq;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyLong;
@@ -283,6 +284,7 @@
 import android.net.shared.NetworkMonitorUtils;
 import android.net.shared.PrivateDnsConfig;
 import android.net.util.MultinetworkPolicyTracker;
+import android.net.wifi.WifiInfo;
 import android.os.BadParcelableException;
 import android.os.BatteryStatsManager;
 import android.os.Binder;
@@ -15572,4 +15574,91 @@
 
         assertNull(readHead.poll(TEST_CALLBACK_TIMEOUT_MS, it -> true));
     }
+
+    @Test
+    public void testIgnoreValidationAfterRoamDisabled() throws Exception {
+        assumeFalse(SdkLevel.isAtLeastT());
+        // testIgnoreValidationAfterRoam off
+        doReturn(-1).when(mResources)
+                .getInteger(R.integer.config_validationFailureAfterRoamIgnoreTimeMillis);
+
+        mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR);
+        mCellNetworkAgent.connect(true);
+        NetworkCapabilities wifiNc1 = new NetworkCapabilities()
+                .addTransportType(TRANSPORT_WIFI)
+                .setTransportInfo(new WifiInfo.Builder().setBssid("AA:AA:AA:AA:AA:AA").build());
+        NetworkCapabilities wifiNc2 = new NetworkCapabilities()
+                .addTransportType(TRANSPORT_WIFI)
+                .setTransportInfo(new WifiInfo.Builder().setBssid("BB:BB:BB:BB:BB:BB").build());
+        final LinkProperties wifiLp = new LinkProperties();
+        wifiLp.setInterfaceName(WIFI_IFNAME);
+        mWiFiNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_WIFI, wifiLp, wifiNc1);
+        mWiFiNetworkAgent.connect(true);
+
+        // The default network will be switching to Wi-Fi Network.
+        final TestNetworkCallback wifiNetworkCallback = new TestNetworkCallback();
+        final NetworkRequest wifiRequest = new NetworkRequest.Builder()
+                .addTransportType(TRANSPORT_WIFI).build();
+        mCm.registerNetworkCallback(wifiRequest, wifiNetworkCallback);
+        wifiNetworkCallback.expectAvailableCallbacksValidated(mWiFiNetworkAgent);
+        registerDefaultNetworkCallbacks();
+        mDefaultNetworkCallback.expectAvailableCallbacksValidated(mWiFiNetworkAgent);
+
+        // Wi-Fi roaming from wifiNc1 to wifiNc2.
+        mWiFiNetworkAgent.setNetworkCapabilities(wifiNc2, true);
+        mWiFiNetworkAgent.setNetworkInvalid(false);
+        mCm.reportNetworkConnectivity(mWiFiNetworkAgent.getNetwork(), false);
+        mDefaultNetworkCallback.expectAvailableCallbacksValidated(mCellNetworkAgent);
+    }
+
+    @Test
+    public void testIgnoreValidationAfterRoamEnabled() throws Exception {
+        assumeFalse(SdkLevel.isAtLeastT());
+        // testIgnoreValidationAfterRoam on
+        doReturn(5000).when(mResources)
+                .getInteger(R.integer.config_validationFailureAfterRoamIgnoreTimeMillis);
+
+        mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR);
+        mCellNetworkAgent.connect(true);
+        NetworkCapabilities wifiNc1 = new NetworkCapabilities()
+                .addTransportType(TRANSPORT_WIFI)
+                .setTransportInfo(new WifiInfo.Builder().setBssid("AA:AA:AA:AA:AA:AA").build());
+        NetworkCapabilities wifiNc2 = new NetworkCapabilities()
+                .addTransportType(TRANSPORT_WIFI)
+                .setTransportInfo(new WifiInfo.Builder().setBssid("BB:BB:BB:BB:BB:BB").build());
+        final LinkProperties wifiLp = new LinkProperties();
+        wifiLp.setInterfaceName(WIFI_IFNAME);
+        mWiFiNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_WIFI, wifiLp, wifiNc1);
+        mWiFiNetworkAgent.connect(true);
+
+        // The default network will be switching to Wi-Fi Network.
+        final TestNetworkCallback wifiNetworkCallback = new TestNetworkCallback();
+        final NetworkRequest wifiRequest = new NetworkRequest.Builder()
+                .addTransportType(TRANSPORT_WIFI).build();
+        mCm.registerNetworkCallback(wifiRequest, wifiNetworkCallback);
+        wifiNetworkCallback.expectAvailableCallbacksValidated(mWiFiNetworkAgent);
+        registerDefaultNetworkCallbacks();
+        mDefaultNetworkCallback.expectAvailableCallbacksValidated(mWiFiNetworkAgent);
+
+        // Wi-Fi roaming from wifiNc1 to wifiNc2.
+        mWiFiNetworkAgent.setNetworkCapabilities(wifiNc2, true);
+        mWiFiNetworkAgent.setNetworkInvalid(false);
+        mCm.reportNetworkConnectivity(mWiFiNetworkAgent.getNetwork(), false);
+
+        // Network validation failed, but the result will be ignored.
+        assertTrue(mCm.getNetworkCapabilities(mWiFiNetworkAgent.getNetwork()).hasCapability(
+                NET_CAPABILITY_VALIDATED));
+        mWiFiNetworkAgent.setNetworkValid(false);
+
+        // Behavior of after config_validationFailureAfterRoamIgnoreTimeMillis
+        ConditionVariable waitForValidationBlock = new ConditionVariable();
+        doReturn(50).when(mResources)
+                .getInteger(R.integer.config_validationFailureAfterRoamIgnoreTimeMillis);
+        // Wi-Fi roaming from wifiNc2 to wifiNc1.
+        mWiFiNetworkAgent.setNetworkCapabilities(wifiNc1, true);
+        mWiFiNetworkAgent.setNetworkInvalid(false);
+        waitForValidationBlock.block(150);
+        mCm.reportNetworkConnectivity(mWiFiNetworkAgent.getNetwork(), false);
+        mDefaultNetworkCallback.expectAvailableCallbacksValidated(mCellNetworkAgent);
+    }
 }