diff --git a/service-t/src/com/android/server/NsdService.java b/service-t/src/com/android/server/NsdService.java
index 6c25d76..9b2f80b 100644
--- a/service-t/src/com/android/server/NsdService.java
+++ b/service-t/src/com/android/server/NsdService.java
@@ -176,7 +176,7 @@
             "mdns_advertiser_allowlist_";
     private static final String MDNS_ALLOWLIST_FLAG_SUFFIX = "_version";
 
-
+    private static final String FORCE_ENABLE_FLAG_FOR_TEST_PREFIX = "test_";
 
     @VisibleForTesting
     static final String MDNS_CONFIG_RUNNING_APP_ACTIVE_IMPORTANCE_CUTOFF =
@@ -1739,6 +1739,10 @@
                         mContext, MdnsFeatureFlags.NSD_LIMIT_LABEL_COUNT))
                 .setIsKnownAnswerSuppressionEnabled(mDeps.isFeatureEnabled(
                         mContext, MdnsFeatureFlags.NSD_KNOWN_ANSWER_SUPPRESSION))
+                .setIsUnicastReplyEnabled(mDeps.isFeatureEnabled(
+                        mContext, MdnsFeatureFlags.NSD_UNICAST_REPLY_ENABLED))
+                .setOverrideProvider(flag -> mDeps.isFeatureEnabled(
+                        mContext, FORCE_ENABLE_FLAG_FOR_TEST_PREFIX + flag))
                 .build();
         mMdnsSocketClient =
                 new MdnsMultinetworkSocketClient(handler.getLooper(), mMdnsSocketProvider,
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsFeatureFlags.java b/service-t/src/com/android/server/connectivity/mdns/MdnsFeatureFlags.java
index 1ad47a3..9466162 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsFeatureFlags.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsFeatureFlags.java
@@ -15,6 +15,9 @@
  */
 package com.android.server.connectivity.mdns;
 
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+
 /**
  * The class that contains mDNS feature flags;
  */
@@ -46,6 +49,14 @@
      */
     public static final String NSD_KNOWN_ANSWER_SUPPRESSION = "nsd_known_answer_suppression";
 
+    /**
+     * A feature flag to control whether unicast replies should be enabled.
+     *
+     * <p>Enabling this feature causes replies to queries with the Query Unicast (QU) flag set to be
+     * sent unicast instead of multicast, as per RFC6762 5.4.
+     */
+    public static final String NSD_UNICAST_REPLY_ENABLED = "nsd_unicast_reply_enabled";
+
     // Flag for offload feature
     public final boolean mIsMdnsOffloadFeatureEnabled;
 
@@ -61,6 +72,36 @@
     // Flag for known-answer suppression
     public final boolean mIsKnownAnswerSuppressionEnabled;
 
+    // Flag to enable replying unicast to queries requesting unicast replies
+    public final boolean mIsUnicastReplyEnabled;
+
+    @Nullable
+    private final FlagOverrideProvider mOverrideProvider;
+
+    /**
+     * A provider that can indicate whether a flag should be force-enabled for testing purposes.
+     */
+    public interface FlagOverrideProvider {
+        /**
+         * Indicates whether the flag should be force-enabled for testing purposes.
+         */
+        boolean isForceEnabledForTest(@NonNull String flag);
+    }
+
+    /**
+     * Indicates whether the flag should be force-enabled for testing purposes.
+     */
+    private boolean isForceEnabledForTest(@NonNull String flag) {
+        return mOverrideProvider != null && mOverrideProvider.isForceEnabledForTest(flag);
+    }
+
+    /**
+     * Indicates whether {@link #NSD_UNICAST_REPLY_ENABLED} is enabled, including for testing.
+     */
+    public boolean isUnicastReplyEnabled() {
+        return mIsUnicastReplyEnabled || isForceEnabledForTest(NSD_UNICAST_REPLY_ENABLED);
+    }
+
     /**
      * The constructor for {@link MdnsFeatureFlags}.
      */
@@ -68,12 +109,16 @@
             boolean includeInetAddressRecordsInProbing,
             boolean isExpiredServicesRemovalEnabled,
             boolean isLabelCountLimitEnabled,
-            boolean isKnownAnswerSuppressionEnabled) {
+            boolean isKnownAnswerSuppressionEnabled,
+            boolean isUnicastReplyEnabled,
+            @Nullable FlagOverrideProvider overrideProvider) {
         mIsMdnsOffloadFeatureEnabled = isOffloadFeatureEnabled;
         mIncludeInetAddressRecordsInProbing = includeInetAddressRecordsInProbing;
         mIsExpiredServicesRemovalEnabled = isExpiredServicesRemovalEnabled;
         mIsLabelCountLimitEnabled = isLabelCountLimitEnabled;
         mIsKnownAnswerSuppressionEnabled = isKnownAnswerSuppressionEnabled;
+        mIsUnicastReplyEnabled = isUnicastReplyEnabled;
+        mOverrideProvider = overrideProvider;
     }
 
 
@@ -90,6 +135,8 @@
         private boolean mIsExpiredServicesRemovalEnabled;
         private boolean mIsLabelCountLimitEnabled;
         private boolean mIsKnownAnswerSuppressionEnabled;
+        private boolean mIsUnicastReplyEnabled;
+        private FlagOverrideProvider mOverrideProvider;
 
         /**
          * The constructor for {@link Builder}.
@@ -100,6 +147,8 @@
             mIsExpiredServicesRemovalEnabled = false;
             mIsLabelCountLimitEnabled = true; // Default enabled.
             mIsKnownAnswerSuppressionEnabled = false;
+            mIsUnicastReplyEnabled = true;
+            mOverrideProvider = null;
         }
 
         /**
@@ -154,6 +203,27 @@
         }
 
         /**
+         * Set whether the unicast reply feature is enabled.
+         *
+         * @see #NSD_UNICAST_REPLY_ENABLED
+         */
+        public Builder setIsUnicastReplyEnabled(boolean isUnicastReplyEnabled) {
+            mIsUnicastReplyEnabled = isUnicastReplyEnabled;
+            return this;
+        }
+
+        /**
+         * Set a {@link FlagOverrideProvider} to be used by {@link #isForceEnabledForTest(String)}.
+         *
+         * If non-null, features that use {@link #isForceEnabledForTest(String)} will use that
+         * provider to query whether the flag should be force-enabled.
+         */
+        public Builder setOverrideProvider(@Nullable FlagOverrideProvider overrideProvider) {
+            mOverrideProvider = overrideProvider;
+            return this;
+        }
+
+        /**
          * Builds a {@link MdnsFeatureFlags} with the arguments supplied to this builder.
          */
         public MdnsFeatureFlags build() {
@@ -161,7 +231,9 @@
                     mIncludeInetAddressRecordsInProbing,
                     mIsExpiredServicesRemovalEnabled,
                     mIsLabelCountLimitEnabled,
-                    mIsKnownAnswerSuppressionEnabled);
+                    mIsKnownAnswerSuppressionEnabled,
+                    mIsUnicastReplyEnabled,
+                    mOverrideProvider);
         }
     }
 }
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsRecord.java b/service-t/src/com/android/server/connectivity/mdns/MdnsRecord.java
index 28bd1b4..4b43989 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsRecord.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsRecord.java
@@ -176,6 +176,16 @@
     }
 
     /**
+     * For questions, returns whether a unicast reply was requested.
+     *
+     * In practice this is identical to {@link #getCacheFlush()}, as the "cache flush" flag in
+     * replies is the same as "unicast reply requested" in questions.
+     */
+    public final boolean isUnicastReplyRequested() {
+        return (cls & MdnsConstants.QCLASS_UNICAST) != 0;
+    }
+
+    /**
      * Returns the record's remaining TTL.
      *
      * If the record was not sent yet (receipt time {@link #RECEIPT_TIME_NOT_SENT}), this is the
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsRecordRepository.java b/service-t/src/com/android/server/connectivity/mdns/MdnsRecordRepository.java
index 6b6632c..585b097 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsRecordRepository.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsRecordRepository.java
@@ -499,26 +499,30 @@
     @Nullable
     public MdnsReplyInfo getReply(MdnsPacket packet, InetSocketAddress src) {
         final long now = SystemClock.elapsedRealtime();
-        final boolean replyUnicast = (packet.flags & MdnsConstants.QCLASS_UNICAST) != 0;
 
         // Use LinkedHashSet for preserving the insert order of the RRs, so that RRs of the same
         // service or host are grouped together (which is more developer-friendly).
         final Set<RecordInfo<?>> answerInfo = new LinkedHashSet<>();
         final Set<RecordInfo<?>> additionalAnswerInfo = new LinkedHashSet<>();
-
+        // Reply unicast if the feature is enabled AND all replied questions request unicast
+        final boolean replyUnicastEnabled = mMdnsFeatureFlags.isUnicastReplyEnabled();
+        boolean replyUnicast = replyUnicastEnabled;
         for (MdnsRecord question : packet.questions) {
             // Add answers from general records
-            addReplyFromService(question, mGeneralRecords, null /* servicePtrRecord */,
-                    null /* serviceSrvRecord */, null /* serviceTxtRecord */, replyUnicast, now,
-                    answerInfo, additionalAnswerInfo, Collections.emptyList());
+            if (addReplyFromService(question, mGeneralRecords, null /* servicePtrRecord */,
+                    null /* serviceSrvRecord */, null /* serviceTxtRecord */, replyUnicastEnabled,
+                    now, answerInfo, additionalAnswerInfo, Collections.emptyList())) {
+                replyUnicast &= question.isUnicastReplyRequested();
+            }
 
             // Add answers from each service
             for (int i = 0; i < mServices.size(); i++) {
                 final ServiceRegistration registration = mServices.valueAt(i);
                 if (registration.exiting || registration.isProbing) continue;
                 if (addReplyFromService(question, registration.allRecords, registration.ptrRecords,
-                        registration.srvRecord, registration.txtRecord, replyUnicast, now,
+                        registration.srvRecord, registration.txtRecord, replyUnicastEnabled, now,
                         answerInfo, additionalAnswerInfo, packet.answers)) {
+                    replyUnicast &= question.isUnicastReplyRequested();
                     registration.repliedServiceCount++;
                     registration.sentPacketCount++;
                 }
@@ -570,6 +574,12 @@
         // Determine the send destination
         final InetSocketAddress dest;
         if (replyUnicast) {
+            // As per RFC6762 5.4, "if the responder has not multicast that record recently (within
+            // one quarter of its TTL), then the responder SHOULD instead multicast the response so
+            // as to keep all the peer caches up to date": this SHOULD is not implemented to
+            // minimize latency for queriers who have just started, so they did not receive previous
+            // multicast responses. Unicast replies are faster as they do not need to wait for the
+            // beacon interval on Wi-Fi.
             dest = src;
         } else if (src.getAddress() instanceof Inet4Address) {
             dest = IPV4_SOCKET_ADDR;
@@ -608,7 +618,7 @@
             @Nullable List<RecordInfo<MdnsPointerRecord>> servicePtrRecords,
             @Nullable RecordInfo<MdnsServiceRecord> serviceSrvRecord,
             @Nullable RecordInfo<MdnsTextRecord> serviceTxtRecord,
-            boolean replyUnicast, long now, @NonNull Set<RecordInfo<?>> answerInfo,
+            boolean replyUnicastEnabled, long now, @NonNull Set<RecordInfo<?>> answerInfo,
             @NonNull Set<RecordInfo<?>> additionalAnswerInfo,
             @NonNull List<MdnsRecord> knownAnswerRecords) {
         boolean hasDnsSdPtrRecordAnswer = false;
@@ -659,7 +669,8 @@
 
             // TODO: responses to probe queries should bypass this check and only ensure the
             // reply is sent 250ms after the last sent time (RFC 6762 p.15)
-            if (!replyUnicast && info.lastAdvertisedTimeMs > 0L
+            if (!(replyUnicastEnabled && question.isUnicastReplyRequested())
+                    && info.lastAdvertisedTimeMs > 0L
                     && now - info.lastAdvertisedTimeMs < MIN_MULTICAST_REPLY_INTERVAL_MS) {
                 continue;
             }