diff --git a/service/Android.bp b/service/Android.bp
index 224fa19..8fa6436 100644
--- a/service/Android.bp
+++ b/service/Android.bp
@@ -206,6 +206,7 @@
     libs: [
         "framework-annotations-lib",
         "framework-connectivity-pre-jarjar",
+        "framework-connectivity-t-pre-jarjar",
         "framework-tethering",
         "framework-wifi",
         "service-connectivity-pre-jarjar",
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsAdvertiser.java b/service/mdns/com/android/server/connectivity/mdns/MdnsAdvertiser.java
index dee78fd..185fac1 100644
--- a/service/mdns/com/android/server/connectivity/mdns/MdnsAdvertiser.java
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsAdvertiser.java
@@ -16,14 +16,401 @@
 
 package com.android.server.connectivity.mdns;
 
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.net.LinkAddress;
+import android.net.Network;
+import android.net.nsd.NsdManager;
+import android.net.nsd.NsdServiceInfo;
+import android.os.Looper;
+import android.util.ArrayMap;
 import android.util.Log;
+import android.util.SparseArray;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Predicate;
 
 /**
  * MdnsAdvertiser manages advertising services per {@link com.android.server.NsdService} requests.
  *
- * TODO: implement
+ * All methods except the constructor must be called on the looper thread.
  */
 public class MdnsAdvertiser {
     private static final String TAG = MdnsAdvertiser.class.getSimpleName();
-    public static final boolean DBG = Log.isLoggable(TAG, Log.DEBUG);
+    static final boolean DBG = Log.isLoggable(TAG, Log.DEBUG);
+
+    private final Looper mLooper;
+    private final AdvertiserCallback mCb;
+
+    // Max-sized buffers to be used as temporary buffer to read/build packets. May be used by
+    // multiple components, but only for self-contained operations in the looper thread, so not
+    // concurrently.
+    // TODO: set according to MTU. 1300 should fit for ethernet MTU 1500 with some overhead.
+    private final byte[] mPacketCreationBuffer = new byte[1300];
+
+    private final MdnsSocketProvider mSocketProvider;
+    private final ArrayMap<Network, InterfaceAdvertiserRequest> mAdvertiserRequests =
+            new ArrayMap<>();
+    private final ArrayMap<MdnsInterfaceSocket, MdnsInterfaceAdvertiser> mAllAdvertisers =
+            new ArrayMap<>();
+    private final SparseArray<Registration> mRegistrations = new SparseArray<>();
+    private final Dependencies mDeps;
+
+    /**
+     * Dependencies for {@link MdnsAdvertiser}, useful for testing.
+     */
+    @VisibleForTesting
+    public static class Dependencies {
+        /**
+         * @see MdnsInterfaceAdvertiser
+         */
+        public MdnsInterfaceAdvertiser makeAdvertiser(@NonNull MdnsInterfaceSocket socket,
+                @NonNull List<LinkAddress> initialAddresses,
+                @NonNull Looper looper, @NonNull byte[] packetCreationBuffer,
+                @NonNull MdnsInterfaceAdvertiser.Callback cb) {
+            // Note NetworkInterface is final and not mockable
+            final String logTag = socket.getInterface().getName();
+            return new MdnsInterfaceAdvertiser(logTag, socket, initialAddresses, looper,
+                    packetCreationBuffer, cb);
+        }
+    }
+
+    private final MdnsInterfaceAdvertiser.Callback mInterfaceAdvertiserCb =
+            new MdnsInterfaceAdvertiser.Callback() {
+        @Override
+        public void onRegisterServiceSucceeded(
+                @NonNull MdnsInterfaceAdvertiser advertiser, int serviceId) {
+            // Wait for all current interfaces to be done probing before notifying of success.
+            if (anyAdvertiser(a -> a.isProbing(serviceId))) return;
+            // The service may still be unregistered/renamed if a conflict is found on a later added
+            // interface, or if a conflicting announcement/reply is detected (RFC6762 9.)
+
+            final Registration registration = mRegistrations.get(serviceId);
+            if (registration == null) {
+                Log.wtf(TAG, "Register succeeded for unknown registration");
+                return;
+            }
+            if (!registration.mNotifiedRegistrationSuccess) {
+                mCb.onRegisterServiceSucceeded(serviceId, registration.getServiceInfo());
+                registration.mNotifiedRegistrationSuccess = true;
+            }
+        }
+
+        @Override
+        public void onServiceConflict(@NonNull MdnsInterfaceAdvertiser advertiser, int serviceId) {
+            // TODO: handle conflicts found after registration (during or after probing)
+        }
+
+        @Override
+        public void onDestroyed(@NonNull MdnsInterfaceSocket socket) {
+            for (int i = mAdvertiserRequests.size() - 1; i >= 0; i--) {
+                if (mAdvertiserRequests.valueAt(i).onAdvertiserDestroyed(socket)) {
+                    mAdvertiserRequests.removeAt(i);
+                }
+            }
+            mAllAdvertisers.remove(socket);
+        }
+    };
+
+    /**
+     * A request for a {@link MdnsInterfaceAdvertiser}.
+     *
+     * This class tracks services to be advertised on all sockets provided via a registered
+     * {@link MdnsSocketProvider.SocketCallback}.
+     */
+    private class InterfaceAdvertiserRequest implements MdnsSocketProvider.SocketCallback {
+        /** Registrations to add to newer MdnsInterfaceAdvertisers when sockets are created. */
+        @NonNull
+        private final SparseArray<Registration> mPendingRegistrations = new SparseArray<>();
+        @NonNull
+        private final ArrayMap<MdnsInterfaceSocket, MdnsInterfaceAdvertiser> mAdvertisers =
+                new ArrayMap<>();
+
+        InterfaceAdvertiserRequest(@Nullable Network requestedNetwork) {
+            mSocketProvider.requestSocket(requestedNetwork, this);
+        }
+
+        /**
+         * Called when an advertiser was destroyed, after all services were unregistered and it sent
+         * exit announcements, or the interface is gone.
+         *
+         * @return true if this {@link InterfaceAdvertiserRequest} should now be deleted.
+         */
+        boolean onAdvertiserDestroyed(@NonNull MdnsInterfaceSocket socket) {
+            mAdvertisers.remove(socket);
+            if (mAdvertisers.size() == 0 && mPendingRegistrations.size() == 0) {
+                // No advertiser is using sockets from this request anymore (in particular for exit
+                // announcements), and there is no registration so newer sockets will not be
+                // necessary, so the request can be unregistered.
+                mSocketProvider.unrequestSocket(this);
+                return true;
+            }
+            return false;
+        }
+
+        /**
+         * Get the ID of a conflicting service, or -1 if none.
+         */
+        int getConflictingService(@NonNull NsdServiceInfo info) {
+            for (int i = 0; i < mPendingRegistrations.size(); i++) {
+                final NsdServiceInfo other = mPendingRegistrations.valueAt(i).getServiceInfo();
+                if (info.getServiceName().equals(other.getServiceName())
+                        && info.getServiceType().equals(other.getServiceType())) {
+                    return mPendingRegistrations.keyAt(i);
+                }
+            }
+            return -1;
+        }
+
+        void addService(int id, Registration registration)
+                throws NameConflictException {
+            final int conflicting = getConflictingService(registration.getServiceInfo());
+            if (conflicting >= 0) {
+                throw new NameConflictException(conflicting);
+            }
+
+            mPendingRegistrations.put(id, registration);
+            for (int i = 0; i < mAdvertisers.size(); i++) {
+                mAdvertisers.valueAt(i).addService(id, registration.getServiceInfo());
+            }
+        }
+
+        void removeService(int id) {
+            mPendingRegistrations.remove(id);
+            for (int i = 0; i < mAdvertisers.size(); i++) {
+                mAdvertisers.valueAt(i).removeService(id);
+            }
+        }
+
+        @Override
+        public void onSocketCreated(@NonNull Network network,
+                @NonNull MdnsInterfaceSocket socket,
+                @NonNull List<LinkAddress> addresses) {
+            MdnsInterfaceAdvertiser advertiser = mAllAdvertisers.get(socket);
+            if (advertiser == null) {
+                advertiser = mDeps.makeAdvertiser(socket, addresses, mLooper, mPacketCreationBuffer,
+                        mInterfaceAdvertiserCb);
+                mAllAdvertisers.put(socket, advertiser);
+                advertiser.start();
+            }
+            mAdvertisers.put(socket, advertiser);
+            for (int i = 0; i < mPendingRegistrations.size(); i++) {
+                try {
+                    advertiser.addService(mPendingRegistrations.keyAt(i),
+                            mPendingRegistrations.valueAt(i).getServiceInfo());
+                } catch (NameConflictException e) {
+                    Log.wtf(TAG, "Name conflict adding services that should have unique names", e);
+                }
+            }
+        }
+
+        @Override
+        public void onInterfaceDestroyed(@NonNull Network network,
+                @NonNull MdnsInterfaceSocket socket) {
+            final MdnsInterfaceAdvertiser advertiser = mAdvertisers.get(socket);
+            if (advertiser != null) advertiser.destroyNow();
+        }
+
+        @Override
+        public void onAddressesChanged(@NonNull Network network,
+                @NonNull MdnsInterfaceSocket socket, @NonNull List<LinkAddress> addresses) {
+            final MdnsInterfaceAdvertiser advertiser = mAdvertisers.get(socket);
+            if (advertiser != null) advertiser.updateAddresses(addresses);
+        }
+    }
+
+    private static class Registration {
+        @NonNull
+        final String mOriginalName;
+        boolean mNotifiedRegistrationSuccess;
+        private int mConflictCount;
+        @NonNull
+        private NsdServiceInfo mServiceInfo;
+
+        private Registration(@NonNull NsdServiceInfo serviceInfo) {
+            this.mOriginalName = serviceInfo.getServiceName();
+            this.mServiceInfo = serviceInfo;
+        }
+
+        /**
+         * Update the registration to use a different service name, after a conflict was found.
+         *
+         * If a name conflict was found during probing or because different advertising requests
+         * used the same name, the registration is attempted again with a new name (here using
+         * a number suffix, (1), (2) etc). Registration success is notified once probing succeeds
+         * with a new name. This matches legacy behavior based on mdnsresponder, and appendix D of
+         * RFC6763.
+         * @return The new service info with the updated name.
+         */
+        @NonNull
+        private NsdServiceInfo updateForConflict() {
+            mConflictCount++;
+            // In case of conflict choose a different service name. After the first conflict use
+            // "Name (2)", then "Name (3)" etc.
+            // TODO: use a hidden method in NsdServiceInfo once MdnsAdvertiser is moved to service-t
+            final NsdServiceInfo newInfo = new NsdServiceInfo();
+            newInfo.setServiceName(mOriginalName + " (" + (mConflictCount + 1) + ")");
+            newInfo.setServiceType(mServiceInfo.getServiceType());
+            for (Map.Entry<String, byte[]> attr : mServiceInfo.getAttributes().entrySet()) {
+                newInfo.setAttribute(attr.getKey(), attr.getValue());
+            }
+            newInfo.setHost(mServiceInfo.getHost());
+            newInfo.setPort(mServiceInfo.getPort());
+            newInfo.setNetwork(mServiceInfo.getNetwork());
+            // interfaceIndex is not set when registering
+
+            mServiceInfo = newInfo;
+            return mServiceInfo;
+        }
+
+        @NonNull
+        public NsdServiceInfo getServiceInfo() {
+            return mServiceInfo;
+        }
+    }
+
+    /**
+     * Callbacks for advertising services.
+     *
+     * Every method is called on the MdnsAdvertiser looper thread.
+     */
+    public interface AdvertiserCallback {
+        /**
+         * Called when a service was successfully registered, after probing.
+         *
+         * @param serviceId ID of the service provided when registering.
+         * @param registeredInfo Registered info, which may be different from the requested info,
+         *                       after probing and possibly choosing alternative service names.
+         */
+        void onRegisterServiceSucceeded(int serviceId, NsdServiceInfo registeredInfo);
+
+        /**
+         * Called when service registration failed.
+         *
+         * @param serviceId ID of the service provided when registering.
+         * @param errorCode One of {@code NsdManager.FAILURE_*}
+         */
+        void onRegisterServiceFailed(int serviceId, int errorCode);
+
+        // Unregistration is notified immediately as success in NsdService so no callback is needed
+        // here.
+    }
+
+    public MdnsAdvertiser(@NonNull Looper looper, @NonNull MdnsSocketProvider socketProvider,
+            @NonNull AdvertiserCallback cb) {
+        this(looper, socketProvider, cb, new Dependencies());
+    }
+
+    @VisibleForTesting
+    MdnsAdvertiser(@NonNull Looper looper, @NonNull MdnsSocketProvider socketProvider,
+            @NonNull AdvertiserCallback cb, @NonNull Dependencies deps) {
+        mLooper = looper;
+        mCb = cb;
+        mSocketProvider = socketProvider;
+        mDeps = deps;
+    }
+
+    private void checkThread() {
+        if (Thread.currentThread() != mLooper.getThread()) {
+            throw new IllegalStateException("This must be called on the looper thread");
+        }
+    }
+
+    /**
+     * Add a service to advertise.
+     * @param id A unique ID for the service.
+     * @param service The service info to advertise.
+     */
+    public void addService(int id, NsdServiceInfo service) {
+        checkThread();
+        if (mRegistrations.get(id) != null) {
+            Log.e(TAG, "Adding duplicate registration for " + service);
+            // TODO (b/264986328): add a more specific error code
+            mCb.onRegisterServiceFailed(id, NsdManager.FAILURE_INTERNAL_ERROR);
+            return;
+        }
+
+        if (DBG) {
+            Log.i(TAG, "Adding service " + service + " with ID " + id);
+        }
+
+        try {
+            final Registration registration = new Registration(service);
+            while (!tryAddRegistration(id, registration)) {
+                registration.updateForConflict();
+            }
+
+            mRegistrations.put(id, registration);
+        } catch (IOException e) {
+            Log.e(TAG, "Error adding service " + service, e);
+            removeService(id);
+            // TODO (b/264986328): add a more specific error code
+            mCb.onRegisterServiceFailed(id, NsdManager.FAILURE_INTERNAL_ERROR);
+        }
+    }
+
+    private boolean tryAddRegistration(int id, @NonNull Registration registration)
+            throws IOException {
+        final NsdServiceInfo serviceInfo = registration.getServiceInfo();
+        final Network network = serviceInfo.getNetwork();
+        try {
+            InterfaceAdvertiserRequest advertiser = mAdvertiserRequests.get(network);
+            if (advertiser == null) {
+                advertiser = new InterfaceAdvertiserRequest(network);
+                mAdvertiserRequests.put(network, advertiser);
+            }
+            advertiser.addService(id, registration);
+        } catch (NameConflictException e) {
+            if (DBG) {
+                Log.i(TAG, "Service name conflicts: " + serviceInfo.getServiceName());
+            }
+            removeService(id);
+            return false;
+        }
+
+        // When adding a service to a specific network, check that it does not conflict with other
+        // registrations advertising on all networks
+        final InterfaceAdvertiserRequest allNetworksAdvertiser = mAdvertiserRequests.get(null);
+        if (network != null && allNetworksAdvertiser != null
+                && allNetworksAdvertiser.getConflictingService(serviceInfo) >= 0) {
+            if (DBG) {
+                Log.i(TAG, "Service conflicts with advertisement on all networks: "
+                        + serviceInfo.getServiceName());
+            }
+            removeService(id);
+            return false;
+        }
+
+        mRegistrations.put(id, registration);
+        return true;
+    }
+
+    /**
+     * Remove a previously added service.
+     * @param id ID used when registering.
+     */
+    public void removeService(int id) {
+        checkThread();
+        if (DBG) {
+            Log.i(TAG, "Removing service with ID " + id);
+        }
+        for (int i = mAdvertiserRequests.size() - 1; i >= 0; i--) {
+            final InterfaceAdvertiserRequest advertiser = mAdvertiserRequests.valueAt(i);
+            advertiser.removeService(id);
+        }
+        mRegistrations.remove(id);
+    }
+
+    private boolean anyAdvertiser(@NonNull Predicate<MdnsInterfaceAdvertiser> predicate) {
+        for (int i = 0; i < mAllAdvertisers.size(); i++) {
+            if (predicate.test(mAllAdvertisers.valueAt(i))) {
+                return true;
+            }
+        }
+        return false;
+    }
 }
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsInterfaceAdvertiser.java b/service/mdns/com/android/server/connectivity/mdns/MdnsInterfaceAdvertiser.java
new file mode 100644
index 0000000..644bdad
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsInterfaceAdvertiser.java
@@ -0,0 +1,175 @@
+/*
+ * 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.connectivity.mdns;
+
+import android.annotation.NonNull;
+import android.net.LinkAddress;
+import android.net.nsd.NsdServiceInfo;
+import android.os.Looper;
+
+import java.util.List;
+
+/**
+ * A class that handles advertising services on a {@link MdnsInterfaceSocket} tied to an interface.
+ */
+public class MdnsInterfaceAdvertiser {
+    private static final boolean DBG = MdnsAdvertiser.DBG;
+    @NonNull
+    private final String mTag;
+    @NonNull
+    private final ProbingCallback mProbingCallback = new ProbingCallback();
+    @NonNull
+    private final AnnouncingCallback mAnnouncingCallback = new AnnouncingCallback();
+    @NonNull
+    private final Callback mCb;
+    @NonNull
+    private final MdnsInterfaceSocket mSocket;
+    @NonNull
+    private final MdnsAnnouncer mAnnouncer;
+    @NonNull
+    private final MdnsProber mProber;
+    @NonNull
+    private final MdnsReplySender mReplySender;
+
+    /**
+     * Callbacks called by {@link MdnsInterfaceAdvertiser} to report status updates.
+     */
+    interface Callback {
+        /**
+         * Called by the advertiser after it successfully registered a service, after probing.
+         */
+        void onRegisterServiceSucceeded(@NonNull MdnsInterfaceAdvertiser advertiser, int serviceId);
+
+        /**
+         * Called by the advertiser when a conflict was found, during or after probing.
+         *
+         * If a conflict is found during probing, the {@link #renameServiceForConflict} must be
+         * called to restart probing and attempt registration with a different name.
+         */
+        void onServiceConflict(@NonNull MdnsInterfaceAdvertiser advertiser, int serviceId);
+
+        /**
+         * Called by the advertiser when it destroyed itself.
+         *
+         * This can happen after a call to {@link #destroyNow()}, or after all services were
+         * unregistered and the advertiser finished sending exit announcements.
+         */
+        void onDestroyed(@NonNull MdnsInterfaceSocket socket);
+    }
+
+    /**
+     * Callbacks from {@link MdnsProber}.
+     */
+    private class ProbingCallback implements
+            MdnsPacketRepeater.PacketRepeaterCallback<MdnsProber.ProbingInfo> {
+        @Override
+        public void onFinished(MdnsProber.ProbingInfo info) {
+            // TODO: probing finished, start announcements
+        }
+    }
+
+    /**
+     * Callbacks from {@link MdnsAnnouncer}.
+     */
+    private class AnnouncingCallback
+            implements MdnsPacketRepeater.PacketRepeaterCallback<MdnsAnnouncer.AnnouncementInfo> {
+        // TODO: implement
+    }
+
+    public MdnsInterfaceAdvertiser(@NonNull String logTag,
+            @NonNull MdnsInterfaceSocket socket, @NonNull List<LinkAddress> initialAddresses,
+            @NonNull Looper looper, @NonNull byte[] packetCreationBuffer, @NonNull Callback cb) {
+        mTag = MdnsInterfaceAdvertiser.class.getSimpleName() + "/" + logTag;
+        mSocket = socket;
+        mCb = cb;
+        mReplySender = new MdnsReplySender(looper, socket, packetCreationBuffer);
+        mAnnouncer = new MdnsAnnouncer(logTag, looper, mReplySender,
+                mAnnouncingCallback);
+        mProber = new MdnsProber(logTag, looper, mReplySender, mProbingCallback);
+    }
+
+    /**
+     * Start the advertiser.
+     *
+     * The advertiser will stop itself when all services are removed and exit announcements sent,
+     * notifying via {@link Callback#onDestroyed}. This can also be triggered manually via
+     * {@link #destroyNow()}.
+     */
+    public void start() {
+        // TODO: implement
+    }
+
+    /**
+     * Start advertising a service.
+     *
+     * @throws NameConflictException There is already a service being advertised with that name.
+     */
+    public void addService(int id, NsdServiceInfo service) throws NameConflictException {
+        // TODO: implement
+    }
+
+    /**
+     * Stop advertising a service.
+     *
+     * This will trigger exit announcements for the service.
+     */
+    public void removeService(int id) {
+        // TODO: implement
+    }
+
+    /**
+     * Update interface addresses used to advertise.
+     *
+     * This causes new address records to be announced.
+     */
+    public void updateAddresses(@NonNull List<LinkAddress> newAddresses) {
+        // TODO: implement
+    }
+
+    /**
+     * Destroy the advertiser immediately, not sending any exit announcement.
+     *
+     * <p>Useful when the underlying network went away. This will trigger an onDestroyed callback.
+     */
+    public void destroyNow() {
+        // TODO: implement
+    }
+
+    /**
+     * Reset a service to the probing state due to a conflict found on the network.
+     */
+    public void restartProbingForConflict(int serviceId) {
+        // TODO: implement
+    }
+
+    /**
+     * Rename a service following a conflict found on the network, and restart probing.
+     */
+    public void renameServiceForConflict(int serviceId, NsdServiceInfo newInfo) {
+        // TODO: implement
+    }
+
+    /**
+     * Indicates whether probing is in progress for the given service on this interface.
+     *
+     * Also returns false if the specified service is not registered.
+     */
+    public boolean isProbing(int serviceId) {
+        // TODO: implement
+        return true;
+    }
+}
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsInterfaceSocket.java b/service/mdns/com/android/server/connectivity/mdns/MdnsInterfaceSocket.java
index 6090415..67c893d 100644
--- a/service/mdns/com/android/server/connectivity/mdns/MdnsInterfaceSocket.java
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsInterfaceSocket.java
@@ -154,13 +154,12 @@
     }
 
     /**
-     * Returns the index of the network interface that this socket is bound to. If the interface
-     * cannot be determined, returns -1.
+     * Returns the network interface that this socket is bound to.
      *
      * <p>This method could be used on any thread.
      */
-    public int getInterfaceIndex() {
-        return mNetworkInterface.getIndex();
+    public NetworkInterface getInterface() {
+        return mNetworkInterface;
     }
 
     /*** Returns whether this socket has joined IPv4 group */
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsReplySender.java b/service/mdns/com/android/server/connectivity/mdns/MdnsReplySender.java
index 1fdbc5c..adf6f4d 100644
--- a/service/mdns/com/android/server/connectivity/mdns/MdnsReplySender.java
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsReplySender.java
@@ -32,14 +32,14 @@
  */
 public class MdnsReplySender {
     @NonNull
-    private final MulticastSocket mSocket;
+    private final MdnsInterfaceSocket mSocket;
     @NonNull
     private final Looper mLooper;
     @NonNull
     private final byte[] mPacketCreationBuffer;
 
     public MdnsReplySender(@NonNull Looper looper,
-            @NonNull MulticastSocket socket, @NonNull byte[] packetCreationBuffer) {
+            @NonNull MdnsInterfaceSocket socket, @NonNull byte[] packetCreationBuffer) {
         mLooper = looper;
         mSocket = socket;
         mPacketCreationBuffer = packetCreationBuffer;
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsSocketProvider.java b/service/mdns/com/android/server/connectivity/mdns/MdnsSocketProvider.java
index b8c324e..d3bf060 100644
--- a/service/mdns/com/android/server/connectivity/mdns/MdnsSocketProvider.java
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsSocketProvider.java
@@ -244,7 +244,7 @@
             // Try to join the group again.
             socketInfo.mSocket.joinGroup(addresses);
 
-            notifyAddressesChanged(network, lp);
+            notifyAddressesChanged(network, socketInfo.mSocket, lp);
         }
     }
 
@@ -355,12 +355,13 @@
         }
     }
 
-    private void notifyAddressesChanged(Network network, LinkProperties lp) {
+    private void notifyAddressesChanged(Network network, MdnsInterfaceSocket socket,
+            LinkProperties lp) {
         for (int i = 0; i < mCallbacksToRequestedNetworks.size(); i++) {
             final Network requestedNetwork = mCallbacksToRequestedNetworks.valueAt(i);
             if (isNetworkMatched(requestedNetwork, network)) {
                 mCallbacksToRequestedNetworks.keyAt(i)
-                        .onAddressesChanged(network, lp.getLinkAddresses());
+                        .onAddressesChanged(network, socket, lp.getLinkAddresses());
             }
         }
     }
@@ -455,6 +456,6 @@
                 @NonNull MdnsInterfaceSocket socket) {}
         /*** Notify the addresses is changed on the network */
         default void onAddressesChanged(@NonNull Network network,
-                @NonNull List<LinkAddress> addresses) {}
+                @NonNull MdnsInterfaceSocket socket, @NonNull List<LinkAddress> addresses) {}
     }
 }
diff --git a/service/mdns/com/android/server/connectivity/mdns/NameConflictException.java b/service/mdns/com/android/server/connectivity/mdns/NameConflictException.java
new file mode 100644
index 0000000..c123d02
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/NameConflictException.java
@@ -0,0 +1,30 @@
+/*
+ * 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.connectivity.mdns;
+
+/**
+ * An exception thrown when a service name conflicts with an existing service.
+ */
+public class NameConflictException extends Exception {
+    /**
+     * ID of the existing service that conflicted.
+     */
+    public final int conflictingServiceId;
+    public NameConflictException(int conflictingServiceId) {
+        this.conflictingServiceId = conflictingServiceId;
+    }
+}
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsAdvertiserTest.kt b/tests/unit/java/com/android/server/connectivity/mdns/MdnsAdvertiserTest.kt
new file mode 100644
index 0000000..e2babb1
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsAdvertiserTest.kt
@@ -0,0 +1,178 @@
+/*
+ * 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.connectivity.mdns
+
+import android.net.InetAddresses.parseNumericAddress
+import android.net.LinkAddress
+import android.net.Network
+import android.net.nsd.NsdServiceInfo
+import android.os.Build
+import android.os.Handler
+import android.os.HandlerThread
+import com.android.server.connectivity.mdns.MdnsAdvertiser.AdvertiserCallback
+import com.android.server.connectivity.mdns.MdnsSocketProvider.SocketCallback
+import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo
+import com.android.testutils.DevSdkIgnoreRunner
+import com.android.testutils.waitForIdle
+import java.util.Objects
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentCaptor
+import org.mockito.ArgumentMatchers.eq
+import org.mockito.Mockito.any
+import org.mockito.Mockito.anyInt
+import org.mockito.Mockito.argThat
+import org.mockito.Mockito.doReturn
+import org.mockito.Mockito.mock
+import org.mockito.Mockito.never
+import org.mockito.Mockito.verify
+
+private const val SERVICE_ID_1 = 1
+private const val SERVICE_ID_2 = 2
+private const val TIMEOUT_MS = 10_000L
+private val TEST_ADDR = parseNumericAddress("2001:db8::123")
+private val TEST_LINKADDR = LinkAddress(TEST_ADDR, 64 /* prefixLength */)
+private val TEST_NETWORK_1 = mock(Network::class.java)
+private val TEST_NETWORK_2 = mock(Network::class.java)
+
+private val SERVICE_1 = NsdServiceInfo("TestServiceName", "_advertisertest._tcp").apply {
+    port = 12345
+    host = TEST_ADDR
+    network = TEST_NETWORK_1
+}
+
+private val ALL_NETWORKS_SERVICE = NsdServiceInfo("TestServiceName", "_advertisertest._tcp").apply {
+    port = 12345
+    host = TEST_ADDR
+    network = null
+}
+
+@RunWith(DevSdkIgnoreRunner::class)
+@IgnoreUpTo(Build.VERSION_CODES.S_V2)
+class MdnsAdvertiserTest {
+    private val thread = HandlerThread(MdnsAdvertiserTest::class.simpleName)
+    private val handler by lazy { Handler(thread.looper) }
+    private val socketProvider = mock(MdnsSocketProvider::class.java)
+    private val cb = mock(AdvertiserCallback::class.java)
+
+    private val mockSocket1 = mock(MdnsInterfaceSocket::class.java)
+    private val mockSocket2 = mock(MdnsInterfaceSocket::class.java)
+    private val mockInterfaceAdvertiser1 = mock(MdnsInterfaceAdvertiser::class.java)
+    private val mockInterfaceAdvertiser2 = mock(MdnsInterfaceAdvertiser::class.java)
+    private val mockDeps = mock(MdnsAdvertiser.Dependencies::class.java)
+
+    @Before
+    fun setUp() {
+        thread.start()
+        doReturn(mockInterfaceAdvertiser1).`when`(mockDeps).makeAdvertiser(eq(mockSocket1),
+                any(), any(), any(), any())
+        doReturn(mockInterfaceAdvertiser2).`when`(mockDeps).makeAdvertiser(eq(mockSocket2),
+                any(), any(), any(), any())
+        doReturn(true).`when`(mockInterfaceAdvertiser1).isProbing(anyInt())
+        doReturn(true).`when`(mockInterfaceAdvertiser2).isProbing(anyInt())
+    }
+
+    @After
+    fun tearDown() {
+        thread.quitSafely()
+    }
+
+    @Test
+    fun testAddService_OneNetwork() {
+        val advertiser = MdnsAdvertiser(thread.looper, socketProvider, cb, mockDeps)
+        postSync { advertiser.addService(SERVICE_ID_1, SERVICE_1) }
+
+        val socketCbCaptor = ArgumentCaptor.forClass(SocketCallback::class.java)
+        verify(socketProvider).requestSocket(eq(TEST_NETWORK_1), socketCbCaptor.capture())
+
+        val socketCb = socketCbCaptor.value
+        postSync { socketCb.onSocketCreated(TEST_NETWORK_1, mockSocket1, listOf(TEST_LINKADDR)) }
+
+        val intAdvCbCaptor = ArgumentCaptor.forClass(MdnsInterfaceAdvertiser.Callback::class.java)
+        verify(mockDeps).makeAdvertiser(eq(mockSocket1),
+                eq(listOf(TEST_LINKADDR)), eq(thread.looper), any(), intAdvCbCaptor.capture())
+
+        doReturn(false).`when`(mockInterfaceAdvertiser1).isProbing(SERVICE_ID_1)
+        postSync { intAdvCbCaptor.value.onRegisterServiceSucceeded(
+                mockInterfaceAdvertiser1, SERVICE_ID_1) }
+        verify(cb).onRegisterServiceSucceeded(eq(SERVICE_ID_1), argThat { it.matches(SERVICE_1) })
+
+        postSync { socketCb.onInterfaceDestroyed(TEST_NETWORK_1, mockSocket1) }
+        verify(mockInterfaceAdvertiser1).destroyNow()
+    }
+
+    @Test
+    fun testAddService_AllNetworks() {
+        val advertiser = MdnsAdvertiser(thread.looper, socketProvider, cb, mockDeps)
+        postSync { advertiser.addService(SERVICE_ID_1, ALL_NETWORKS_SERVICE) }
+
+        val socketCbCaptor = ArgumentCaptor.forClass(SocketCallback::class.java)
+        verify(socketProvider).requestSocket(eq(ALL_NETWORKS_SERVICE.network),
+                socketCbCaptor.capture())
+
+        val socketCb = socketCbCaptor.value
+        postSync { socketCb.onSocketCreated(TEST_NETWORK_1, mockSocket1, listOf(TEST_LINKADDR)) }
+        postSync { socketCb.onSocketCreated(TEST_NETWORK_2, mockSocket2, listOf(TEST_LINKADDR)) }
+
+        val intAdvCbCaptor1 = ArgumentCaptor.forClass(MdnsInterfaceAdvertiser.Callback::class.java)
+        val intAdvCbCaptor2 = ArgumentCaptor.forClass(MdnsInterfaceAdvertiser.Callback::class.java)
+        verify(mockDeps).makeAdvertiser(eq(mockSocket1), eq(listOf(TEST_LINKADDR)),
+                eq(thread.looper), any(), intAdvCbCaptor1.capture())
+        verify(mockDeps).makeAdvertiser(eq(mockSocket2), eq(listOf(TEST_LINKADDR)),
+                eq(thread.looper), any(), intAdvCbCaptor2.capture())
+
+        doReturn(false).`when`(mockInterfaceAdvertiser1).isProbing(SERVICE_ID_1)
+        postSync { intAdvCbCaptor1.value.onRegisterServiceSucceeded(
+                mockInterfaceAdvertiser1, SERVICE_ID_1) }
+
+        // Need both advertisers to finish probing and call onRegisterServiceSucceeded
+        verify(cb, never()).onRegisterServiceSucceeded(anyInt(), any())
+        doReturn(false).`when`(mockInterfaceAdvertiser2).isProbing(SERVICE_ID_1)
+        postSync { intAdvCbCaptor2.value.onRegisterServiceSucceeded(
+                mockInterfaceAdvertiser2, SERVICE_ID_1) }
+        verify(cb).onRegisterServiceSucceeded(eq(SERVICE_ID_1),
+                argThat { it.matches(ALL_NETWORKS_SERVICE) })
+
+        // Unregister the service
+        postSync { advertiser.removeService(SERVICE_ID_1) }
+        verify(mockInterfaceAdvertiser1).removeService(SERVICE_ID_1)
+        verify(mockInterfaceAdvertiser2).removeService(SERVICE_ID_1)
+
+        // Interface advertisers call onDestroyed after sending exit announcements
+        postSync { intAdvCbCaptor1.value.onDestroyed(mockSocket1) }
+        verify(socketProvider, never()).unrequestSocket(any())
+        postSync { intAdvCbCaptor2.value.onDestroyed(mockSocket2) }
+        verify(socketProvider).unrequestSocket(socketCb)
+    }
+
+    private fun postSync(r: () -> Unit) {
+        handler.post(r)
+        handler.waitForIdle(TIMEOUT_MS)
+    }
+}
+
+// NsdServiceInfo does not implement equals; this is useful to use in argument matchers
+private fun NsdServiceInfo.matches(other: NsdServiceInfo): Boolean {
+    return Objects.equals(serviceName, other.serviceName) &&
+            Objects.equals(serviceType, other.serviceType) &&
+            Objects.equals(attributes, other.attributes) &&
+            Objects.equals(host, other.host) &&
+            port == other.port &&
+            Objects.equals(network, other.network)
+}
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsAnnouncerTest.kt b/tests/unit/java/com/android/server/connectivity/mdns/MdnsAnnouncerTest.kt
index e9325d5..2051e0c 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsAnnouncerTest.kt
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsAnnouncerTest.kt
@@ -28,7 +28,6 @@
 import java.net.Inet6Address
 import java.net.InetAddress
 import java.net.InetSocketAddress
-import java.net.MulticastSocket
 import kotlin.test.assertEquals
 import kotlin.test.assertTrue
 import org.junit.After
@@ -55,7 +54,7 @@
 class MdnsAnnouncerTest {
 
     private val thread = HandlerThread(MdnsAnnouncerTest::class.simpleName)
-    private val socket = mock(MulticastSocket::class.java)
+    private val socket = mock(MdnsInterfaceSocket::class.java)
     private val buffer = ByteArray(1500)
 
     @Before
@@ -71,8 +70,7 @@
     private class TestAnnouncementInfo(
         announcedRecords: List<MdnsRecord>,
         additionalRecords: List<MdnsRecord>
-    )
-        : AnnouncementInfo(announcedRecords, additionalRecords, destinationsSupplier) {
+    ) : AnnouncementInfo(announcedRecords, additionalRecords, destinationsSupplier) {
         override fun getDelayMs(nextIndex: Int) =
                 if (nextIndex < FIRST_ANNOUNCES_COUNT) {
                     FIRST_ANNOUNCES_DELAY
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsProberTest.kt b/tests/unit/java/com/android/server/connectivity/mdns/MdnsProberTest.kt
index 419121c..a98a4b2 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsProberTest.kt
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsProberTest.kt
@@ -26,7 +26,6 @@
 import com.android.testutils.DevSdkIgnoreRunner
 import java.net.DatagramPacket
 import java.net.InetSocketAddress
-import java.net.MulticastSocket
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.TimeUnit
 import kotlin.test.assertEquals
@@ -57,7 +56,7 @@
 @IgnoreUpTo(Build.VERSION_CODES.S_V2)
 class MdnsProberTest {
     private val thread = HandlerThread(MdnsProberTest::class.simpleName)
-    private val socket = mock(MulticastSocket::class.java)
+    private val socket = mock(MdnsInterfaceSocket::class.java)
     @Suppress("UNCHECKED_CAST")
     private val cb = mock(MdnsPacketRepeater.PacketRepeaterCallback::class.java)
         as MdnsPacketRepeater.PacketRepeaterCallback<ProbingInfo>
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
index 2bb61a6a..ef73030 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
@@ -159,7 +159,8 @@
         }
 
         @Override
-        public void onAddressesChanged(Network network, List<LinkAddress> addresses) {
+        public void onAddressesChanged(Network network, MdnsInterfaceSocket socket,
+                List<LinkAddress> addresses) {
             mHistory.add(new AddressesChangedEvent(network, addresses));
         }