diff --git a/Tethering/src/com/android/networkstack/tethering/UpstreamNetworkMonitor.java b/Tethering/src/com/android/networkstack/tethering/UpstreamNetworkMonitor.java
index cd27318..69471a1 100644
--- a/Tethering/src/com/android/networkstack/tethering/UpstreamNetworkMonitor.java
+++ b/Tethering/src/com/android/networkstack/tethering/UpstreamNetworkMonitor.java
@@ -398,10 +398,10 @@
             // notifications (e.g. matching more than one of our callbacks).
             //
             // Also, it can happen that onLinkPropertiesChanged is called after
-            // onLost removed the state from mNetworkMap. This appears to be due
-            // to a bug in disconnectAndDestroyNetwork, which calls
-            // nai.clatd.update() after the onLost callbacks.
-            // TODO: fix the bug and make this method void.
+            // onLost removed the state from mNetworkMap. This is due to a bug
+            // in disconnectAndDestroyNetwork, which calls nai.clatd.update()
+            // after the onLost callbacks. This was fixed in S.
+            // TODO: make this method void when R is no longer supported.
             return null;
         }
 
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 564512a..15b666a 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -6299,8 +6299,7 @@
     // there may not be a strict 1:1 correlation between the two.
     private final NetIdManager mNetIdManager;
 
-    // NetworkAgentInfo keyed off its connecting messenger
-    // TODO - eval if we can reduce the number of lists/hashmaps/sparsearrays
+    // Tracks all NetworkAgents that are currently registered.
     // NOTE: Only should be accessed on ConnectivityServiceThread, except dump().
     private final ArraySet<NetworkAgentInfo> mNetworkAgentInfos = new ArraySet<>();
 
@@ -7452,7 +7451,7 @@
     public void handleUpdateLinkProperties(NetworkAgentInfo nai, LinkProperties newLp) {
         ensureRunningOnConnectivityServiceThread();
 
-        if (getNetworkAgentInfoForNetId(nai.network.getNetId()) != nai) {
+        if (!mNetworkAgentInfos.contains(nai)) {
             // Ignore updates for disconnected networks
             return;
         }
diff --git a/tests/cts/net/util/java/android/net/cts/util/CtsNetUtils.java b/tests/cts/net/util/java/android/net/cts/util/CtsNetUtils.java
index 1fbe3b8..b32218b 100644
--- a/tests/cts/net/util/java/android/net/cts/util/CtsNetUtils.java
+++ b/tests/cts/net/util/java/android/net/cts/util/CtsNetUtils.java
@@ -87,6 +87,7 @@
     private static final int PRIVATE_DNS_SETTING_TIMEOUT_MS = 10_000;
     private static final int CONNECTIVITY_CHANGE_TIMEOUT_SECS = 30;
     private static final String PRIVATE_DNS_MODE_OPPORTUNISTIC = "opportunistic";
+    private static final String PRIVATE_DNS_MODE_STRICT = "hostname";
     public static final int HTTP_PORT = 80;
     public static final String TEST_HOST = "connectivitycheck.gstatic.com";
     public static final String HTTP_REQUEST =
@@ -523,12 +524,17 @@
     }
 
     public void restorePrivateDnsSetting() throws InterruptedException {
-        if (mOldPrivateDnsMode == null || mOldPrivateDnsSpecifier == null) {
-            return;
+        if (mOldPrivateDnsMode == null) {
+            fail("restorePrivateDnsSetting without storing settings first");
         }
         // restore private DNS setting
-        if ("hostname".equals(mOldPrivateDnsMode)) {
+        if (PRIVATE_DNS_MODE_STRICT.equals(mOldPrivateDnsMode)) {
             setPrivateDnsStrictMode(mOldPrivateDnsSpecifier);
+
+            // In case of invalid setting, still restore it but fail the test
+            if (mOldPrivateDnsSpecifier == null) {
+                fail("Invalid private DNS setting: no hostname specified in strict mode");
+            }
             awaitPrivateDnsSetting("restorePrivateDnsSetting timeout",
                     mCm.getActiveNetwork(),
                     mOldPrivateDnsSpecifier, true);
@@ -539,13 +545,14 @@
 
     public void setPrivateDnsStrictMode(String server) {
         // To reduce flake rate, set PRIVATE_DNS_SPECIFIER before PRIVATE_DNS_MODE. This ensures
-        // that if the previous private DNS mode was not "hostname", the system only sees one
+        // that if the previous private DNS mode was not strict, the system only sees one
         // EVENT_PRIVATE_DNS_SETTINGS_CHANGED event instead of two.
         Settings.Global.putString(mCR, Settings.Global.PRIVATE_DNS_SPECIFIER, server);
         final String mode = Settings.Global.getString(mCR, Settings.Global.PRIVATE_DNS_MODE);
-        // If current private DNS mode is "hostname", we only need to set PRIVATE_DNS_SPECIFIER.
-        if (!"hostname".equals(mode)) {
-            Settings.Global.putString(mCR, Settings.Global.PRIVATE_DNS_MODE, "hostname");
+        // If current private DNS mode is strict, we only need to set PRIVATE_DNS_SPECIFIER.
+        if (!PRIVATE_DNS_MODE_STRICT.equals(mode)) {
+            Settings.Global.putString(mCR, Settings.Global.PRIVATE_DNS_MODE,
+                    PRIVATE_DNS_MODE_STRICT);
         }
     }
 
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index 40da20b..a9612de 100644
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -412,6 +412,7 @@
             UserHandle.getUid(TEST_WORK_PROFILE_USER_ID, TEST_APP_ID);
     private static final String CLAT_PREFIX = "v4-";
     private static final String MOBILE_IFNAME = "test_rmnet_data0";
+    private static final String CLAT_MOBILE_IFNAME = CLAT_PREFIX + MOBILE_IFNAME;
     private static final String WIFI_IFNAME = "test_wlan0";
     private static final String WIFI_WOL_IFNAME = "test_wlan_wol";
     private static final String VPN_IFNAME = "tun10042";
@@ -8359,10 +8360,10 @@
     private LinkProperties makeClatLinkProperties(LinkAddress la) {
         LinkAddress clatAddress = la;
         LinkProperties stacked = new LinkProperties();
-        stacked.setInterfaceName(CLAT_PREFIX + MOBILE_IFNAME);
+        stacked.setInterfaceName(CLAT_MOBILE_IFNAME);
         RouteInfo ipv4Default = new RouteInfo(
                 new LinkAddress(Inet4Address.ANY, 0),
-                clatAddress.getAddress(), CLAT_PREFIX + MOBILE_IFNAME);
+                clatAddress.getAddress(), CLAT_MOBILE_IFNAME);
         stacked.addRoute(ipv4Default);
         stacked.addLinkAddress(clatAddress);
         return stacked;
@@ -8387,12 +8388,12 @@
         final String kOtherNat64PrefixString = "64:ff9b::";
         final IpPrefix kOtherNat64Prefix = new IpPrefix(
                 InetAddress.getByName(kOtherNat64PrefixString), 96);
-        final RouteInfo defaultRoute = new RouteInfo((IpPrefix) null, myIpv6.getAddress(),
-                                                     MOBILE_IFNAME);
+        final RouteInfo ipv6Default =
+                new RouteInfo((IpPrefix) null, myIpv6.getAddress(), MOBILE_IFNAME);
         final RouteInfo ipv6Subnet = new RouteInfo(myIpv6, null, MOBILE_IFNAME);
         final RouteInfo ipv4Subnet = new RouteInfo(myIpv4, null, MOBILE_IFNAME);
-        final RouteInfo stackedDefault = new RouteInfo((IpPrefix) null, myIpv4.getAddress(),
-                                                       CLAT_PREFIX + MOBILE_IFNAME);
+        final RouteInfo stackedDefault =
+                new RouteInfo((IpPrefix) null, myIpv4.getAddress(), CLAT_MOBILE_IFNAME);
 
         final NetworkRequest networkRequest = new NetworkRequest.Builder()
                 .addTransportType(TRANSPORT_CELLULAR)
@@ -8405,7 +8406,7 @@
         final LinkProperties cellLp = new LinkProperties();
         cellLp.setInterfaceName(MOBILE_IFNAME);
         cellLp.addLinkAddress(myIpv6);
-        cellLp.addRoute(defaultRoute);
+        cellLp.addRoute(ipv6Default);
         cellLp.addRoute(ipv6Subnet);
         mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR, cellLp);
         reset(mMockDnsResolver);
@@ -8413,12 +8414,12 @@
 
         // Connect with ipv6 link properties. Expect prefix discovery to be started.
         mCellNetworkAgent.connect(true);
-        final int cellNetId = mCellNetworkAgent.getNetwork().netId;
+        int cellNetId = mCellNetworkAgent.getNetwork().netId;
         waitForIdle();
 
         verify(mMockNetd, times(1)).networkCreate(nativeNetworkConfigPhysical(cellNetId,
                 INetd.PERMISSION_NONE));
-        assertRoutesAdded(cellNetId, ipv6Subnet, defaultRoute);
+        assertRoutesAdded(cellNetId, ipv6Subnet, ipv6Default);
         verify(mMockDnsResolver, times(1)).createNetworkCache(eq(cellNetId));
         verify(mMockNetd, times(1)).networkAddInterface(cellNetId, MOBILE_IFNAME);
         verify(mDeps).reportNetworkInterfaceForTransports(mServiceContext,
@@ -8449,7 +8450,7 @@
         verifyNoMoreInteractions(mMockDnsResolver);
         reset(mMockNetd);
         reset(mMockDnsResolver);
-        when(mMockNetd.interfaceGetCfg(CLAT_PREFIX + MOBILE_IFNAME))
+        when(mMockNetd.interfaceGetCfg(CLAT_MOBILE_IFNAME))
                 .thenReturn(getClatInterfaceConfigParcel(myIpv4));
 
         // Remove IPv4 address. Expect prefix discovery to be started again.
@@ -8471,13 +8472,13 @@
         verify(mMockNetd, times(1)).clatdStart(MOBILE_IFNAME, kNat64Prefix.toString());
 
         // Clat iface comes up. Expect stacked link to be added.
-        clat.interfaceLinkStateChanged(CLAT_PREFIX + MOBILE_IFNAME, true);
+        clat.interfaceLinkStateChanged(CLAT_MOBILE_IFNAME, true);
         networkCallback.expectCallback(CallbackEntry.LINK_PROPERTIES_CHANGED, mCellNetworkAgent);
         List<LinkProperties> stackedLps = mCm.getLinkProperties(mCellNetworkAgent.getNetwork())
                 .getStackedLinks();
         assertEquals(makeClatLinkProperties(myIpv4), stackedLps.get(0));
         assertRoutesAdded(cellNetId, stackedDefault);
-        verify(mMockNetd, times(1)).networkAddInterface(cellNetId, CLAT_PREFIX + MOBILE_IFNAME);
+        verify(mMockNetd, times(1)).networkAddInterface(cellNetId, CLAT_MOBILE_IFNAME);
         // Change trivial linkproperties and see if stacked link is preserved.
         cellLp.addDnsServer(InetAddress.getByName("8.8.8.8"));
         mCellNetworkAgent.sendLinkProperties(cellLp);
@@ -8500,7 +8501,7 @@
                     new int[] { TRANSPORT_CELLULAR });
         }
         reset(mMockNetd);
-        when(mMockNetd.interfaceGetCfg(CLAT_PREFIX + MOBILE_IFNAME))
+        when(mMockNetd.interfaceGetCfg(CLAT_MOBILE_IFNAME))
                 .thenReturn(getClatInterfaceConfigParcel(myIpv4));
         // Change the NAT64 prefix without first removing it.
         // Expect clatd to be stopped and started with the new prefix.
@@ -8510,16 +8511,16 @@
                 (lp) -> lp.getStackedLinks().size() == 0);
         verify(mMockNetd, times(1)).clatdStop(MOBILE_IFNAME);
         assertRoutesRemoved(cellNetId, stackedDefault);
-        verify(mMockNetd, times(1)).networkRemoveInterface(cellNetId, CLAT_PREFIX + MOBILE_IFNAME);
+        verify(mMockNetd, times(1)).networkRemoveInterface(cellNetId, CLAT_MOBILE_IFNAME);
 
         verify(mMockNetd, times(1)).clatdStart(MOBILE_IFNAME, kOtherNat64Prefix.toString());
         networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
                 (lp) -> lp.getNat64Prefix().equals(kOtherNat64Prefix));
-        clat.interfaceLinkStateChanged(CLAT_PREFIX + MOBILE_IFNAME, true);
+        clat.interfaceLinkStateChanged(CLAT_MOBILE_IFNAME, true);
         networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
                 (lp) -> lp.getStackedLinks().size() == 1);
         assertRoutesAdded(cellNetId, stackedDefault);
-        verify(mMockNetd, times(1)).networkAddInterface(cellNetId, CLAT_PREFIX + MOBILE_IFNAME);
+        verify(mMockNetd, times(1)).networkAddInterface(cellNetId, CLAT_MOBILE_IFNAME);
         reset(mMockNetd);
 
         // Add ipv4 address, expect that clatd and prefix discovery are stopped and stacked
@@ -8542,14 +8543,14 @@
         assertRoutesRemoved(cellNetId, stackedDefault);
 
         // The interface removed callback happens but has no effect after stop is called.
-        clat.interfaceRemoved(CLAT_PREFIX + MOBILE_IFNAME);
+        clat.interfaceRemoved(CLAT_MOBILE_IFNAME);
         networkCallback.assertNoCallback();
-        verify(mMockNetd, times(1)).networkRemoveInterface(cellNetId, CLAT_PREFIX + MOBILE_IFNAME);
+        verify(mMockNetd, times(1)).networkRemoveInterface(cellNetId, CLAT_MOBILE_IFNAME);
         verifyNoMoreInteractions(mMockNetd);
         verifyNoMoreInteractions(mMockDnsResolver);
         reset(mMockNetd);
         reset(mMockDnsResolver);
-        when(mMockNetd.interfaceGetCfg(CLAT_PREFIX + MOBILE_IFNAME))
+        when(mMockNetd.interfaceGetCfg(CLAT_MOBILE_IFNAME))
                 .thenReturn(getClatInterfaceConfigParcel(myIpv4));
 
         // Stopping prefix discovery causes netd to tell us that the NAT64 prefix is gone.
@@ -8572,11 +8573,11 @@
         verify(mMockNetd, times(1)).clatdStart(MOBILE_IFNAME, kNat64Prefix.toString());
 
         // Clat iface comes up. Expect stacked link to be added.
-        clat.interfaceLinkStateChanged(CLAT_PREFIX + MOBILE_IFNAME, true);
+        clat.interfaceLinkStateChanged(CLAT_MOBILE_IFNAME, true);
         networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
                 (lp) -> lp.getStackedLinks().size() == 1 && lp.getNat64Prefix() != null);
         assertRoutesAdded(cellNetId, stackedDefault);
-        verify(mMockNetd, times(1)).networkAddInterface(cellNetId, CLAT_PREFIX + MOBILE_IFNAME);
+        verify(mMockNetd, times(1)).networkAddInterface(cellNetId, CLAT_MOBILE_IFNAME);
 
         // NAT64 prefix is removed. Expect that clat is stopped.
         mService.mResolverUnsolEventCallback.onNat64PrefixEvent(makeNat64PrefixEvent(
@@ -8589,13 +8590,54 @@
         verify(mMockNetd, times(1)).clatdStop(MOBILE_IFNAME);
         networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
                 (lp) -> lp.getStackedLinks().size() == 0);
-        verify(mMockNetd, times(1)).networkRemoveInterface(cellNetId, CLAT_PREFIX + MOBILE_IFNAME);
-        verify(mMockNetd, times(1)).interfaceGetCfg(CLAT_PREFIX + MOBILE_IFNAME);
-        verifyNoMoreInteractions(mMockNetd);
+        verify(mMockNetd, times(1)).networkRemoveInterface(cellNetId, CLAT_MOBILE_IFNAME);
+        verify(mMockNetd, times(1)).interfaceGetCfg(CLAT_MOBILE_IFNAME);
         // Clean up.
         mCellNetworkAgent.disconnect();
         networkCallback.expectCallback(CallbackEntry.LOST, mCellNetworkAgent);
         networkCallback.assertNoCallback();
+        verify(mMockNetd, times(1)).idletimerRemoveInterface(eq(MOBILE_IFNAME), anyInt(),
+                eq(Integer.toString(TRANSPORT_CELLULAR)));
+        verify(mMockNetd).networkDestroy(cellNetId);
+        verifyNoMoreInteractions(mMockNetd);
+        reset(mMockNetd);
+
+        // Test disconnecting a network that is running 464xlat.
+
+        // Connect a network with a NAT64 prefix.
+        when(mMockNetd.interfaceGetCfg(CLAT_MOBILE_IFNAME))
+                .thenReturn(getClatInterfaceConfigParcel(myIpv4));
+        cellLp.setNat64Prefix(kNat64Prefix);
+        mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR, cellLp);
+        mCellNetworkAgent.connect(false /* validated */);
+        networkCallback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
+        cellNetId = mCellNetworkAgent.getNetwork().netId;
+        verify(mMockNetd, times(1)).networkCreate(nativeNetworkConfigPhysical(cellNetId,
+                INetd.PERMISSION_NONE));
+        assertRoutesAdded(cellNetId, ipv6Subnet, ipv6Default);
+
+        // Clatd is started and clat iface comes up. Expect stacked link to be added.
+        verify(mMockNetd).clatdStart(MOBILE_IFNAME, kNat64Prefix.toString());
+        clat = getNat464Xlat(mCellNetworkAgent);
+        clat.interfaceLinkStateChanged(CLAT_MOBILE_IFNAME, true /* up */);
+        networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
+                (lp) -> lp.getStackedLinks().size() == 1
+                        && lp.getNat64Prefix().equals(kNat64Prefix));
+        verify(mMockNetd).networkAddInterface(cellNetId, CLAT_MOBILE_IFNAME);
+        // assertRoutesAdded sees all calls since last mMockNetd reset, so expect IPv6 routes again.
+        assertRoutesAdded(cellNetId, ipv6Subnet, ipv6Default, stackedDefault);
+        reset(mMockNetd);
+
+        // Disconnect the network. clat is stopped and the network is destroyed.
+        mCellNetworkAgent.disconnect();
+        networkCallback.expectCallback(CallbackEntry.LOST, mCellNetworkAgent);
+        networkCallback.assertNoCallback();
+        verify(mMockNetd).clatdStop(MOBILE_IFNAME);
+        verify(mMockNetd).idletimerRemoveInterface(eq(MOBILE_IFNAME), anyInt(),
+                eq(Integer.toString(TRANSPORT_CELLULAR)));
+        verify(mMockNetd).networkDestroy(cellNetId);
+        verifyNoMoreInteractions(mMockNetd);
+
         mCm.unregisterNetworkCallback(networkCallback);
     }
 
@@ -9740,6 +9782,8 @@
     }
 
     private void assertRoutesAdded(int netId, RouteInfo... routes) throws Exception {
+        // TODO: add @JavaDerive(equals=true) to RouteInfoParcel, use eq() directly, and delete
+        // assertRouteInfoParcelMatches above.
         ArgumentCaptor<RouteInfoParcel> captor = ArgumentCaptor.forClass(RouteInfoParcel.class);
         verify(mMockNetd, times(routes.length)).networkAddRouteParcel(eq(netId), captor.capture());
         for (int i = 0; i < routes.length; i++) {