diff --git a/apishim/common/com/android/networkstack/apishim/common/ShimUtils.java b/apishim/common/com/android/networkstack/apishim/common/ShimUtils.java
index 648751b..a7bf921 100644
--- a/apishim/common/com/android/networkstack/apishim/common/ShimUtils.java
+++ b/apishim/common/com/android/networkstack/apishim/common/ShimUtils.java
@@ -44,13 +44,6 @@
     }
 
     /**
-     * Check whether the device supports in-development or final R networking APIs.
-     */
-    public static boolean isAtLeastR() {
-        return isReleaseOrDevelopmentApiAbove(Build.VERSION_CODES.Q);
-    }
-
-    /**
      * Check whether the device supports in-development or final S networking APIs.
      */
     public static boolean isAtLeastS() {
diff --git a/src/android/net/ip/IpClient.java b/src/android/net/ip/IpClient.java
index 868c63b..0106d59 100644
--- a/src/android/net/ip/IpClient.java
+++ b/src/android/net/ip/IpClient.java
@@ -44,7 +44,6 @@
 import static android.net.ip.IpClient.IpClientCommands.CMD_UPDATE_APF_DATA_SNAPSHOT;
 import static android.net.ip.IpClient.IpClientCommands.CMD_UPDATE_HTTP_PROXY;
 import static android.net.ip.IpClient.IpClientCommands.CMD_UPDATE_L2INFORMATION;
-import static android.net.ip.IpClient.IpClientCommands.CMD_UPDATE_L2KEY_CLUSTER;
 import static android.net.ip.IpClient.IpClientCommands.CMD_UPDATE_TCP_BUFFER_SIZES;
 import static android.net.ip.IpClient.IpClientCommands.EVENT_DHCPACTION_TIMEOUT;
 import static android.net.ip.IpClient.IpClientCommands.EVENT_IPV6_AUTOCONF_TIMEOUT;
@@ -134,7 +133,6 @@
 import android.net.shared.ProvisioningConfiguration;
 import android.net.shared.ProvisioningConfiguration.ScanResultInfo;
 import android.net.shared.ProvisioningConfiguration.ScanResultInfo.InformationElement;
-import android.os.Build;
 import android.os.ConditionVariable;
 import android.os.Handler;
 import android.os.IBinder;
@@ -152,7 +150,6 @@
 import android.text.format.DateUtils;
 import android.util.LocalLog;
 import android.util.Log;
-import android.util.Pair;
 import android.util.SparseArray;
 
 import androidx.annotation.NonNull;
@@ -601,16 +598,15 @@
         static final int EVENT_READ_PACKET_FILTER_COMPLETE = 12;
         static final int CMD_ADD_KEEPALIVE_PACKET_FILTER_TO_APF = 13;
         static final int CMD_REMOVE_KEEPALIVE_PACKET_FILTER_FROM_APF = 14;
-        static final int CMD_UPDATE_L2KEY_CLUSTER = 15;
-        static final int CMD_COMPLETE_PRECONNECTION = 16;
-        static final int CMD_UPDATE_L2INFORMATION = 17;
-        static final int CMD_SET_DTIM_MULTIPLIER_AFTER_DELAY = 18;
-        static final int CMD_UPDATE_APF_CAPABILITIES = 19;
-        static final int EVENT_IPV6_AUTOCONF_TIMEOUT = 20;
-        static final int CMD_UPDATE_APF_DATA_SNAPSHOT = 21;
-        static final int EVENT_NUD_FAILURE_QUERY_TIMEOUT = 22;
-        static final int EVENT_NUD_FAILURE_QUERY_SUCCESS = 23;
-        static final int EVENT_NUD_FAILURE_QUERY_FAILURE = 24;
+        static final int CMD_COMPLETE_PRECONNECTION = 15;
+        static final int CMD_UPDATE_L2INFORMATION = 16;
+        static final int CMD_SET_DTIM_MULTIPLIER_AFTER_DELAY = 17;
+        static final int CMD_UPDATE_APF_CAPABILITIES = 18;
+        static final int EVENT_IPV6_AUTOCONF_TIMEOUT = 19;
+        static final int CMD_UPDATE_APF_DATA_SNAPSHOT = 20;
+        static final int EVENT_NUD_FAILURE_QUERY_TIMEOUT = 21;
+        static final int EVENT_NUD_FAILURE_QUERY_SUCCESS = 22;
+        static final int EVENT_NUD_FAILURE_QUERY_FAILURE = 23;
         // Internal commands to use instead of trying to call transitionTo() inside
         // a given State's enter() method. Calling transitionTo() from enter/exit
         // encounters a Log.wtf() that can cause trouble on eng builds.
@@ -635,11 +631,6 @@
     private static final int MAX_PACKET_RECORDS = 100;
 
     @VisibleForTesting
-    static final String CONFIG_MIN_RDNSS_LIFETIME = "ipclient_min_rdnss_lifetime";
-    private static final int DEFAULT_MIN_RDNSS_LIFETIME =
-            ShimUtils.isReleaseOrDevelopmentApiAbove(Build.VERSION_CODES.Q) ? 120 : 0;
-
-    @VisibleForTesting
     static final String CONFIG_ACCEPT_RA_MIN_LFT = "ipclient_accept_ra_min_lft";
     @VisibleForTesting
     static final int DEFAULT_ACCEPT_RA_MIN_LFT = 180;
@@ -799,9 +790,6 @@
     @Nullable
     private final DevicePolicyManager mDevicePolicyManager;
 
-    // Ignore nonzero RDNSS option lifetimes below this value. 0 = disabled.
-    private final int mMinRdnssLifetimeSec;
-
     // Ignore any nonzero RA section with lifetime below this value.
     private final int mAcceptRaMinLft;
 
@@ -1063,8 +1051,6 @@
         mDhcp6PrefixDelegationEnabled = mDependencies.isFeatureEnabled(mContext,
                 IPCLIENT_DHCPV6_PREFIX_DELEGATION_VERSION);
 
-        mMinRdnssLifetimeSec = mDependencies.getDeviceConfigPropertyInt(
-                CONFIG_MIN_RDNSS_LIFETIME, DEFAULT_MIN_RDNSS_LIFETIME);
         mAcceptRaMinLft = mDependencies.getDeviceConfigPropertyInt(CONFIG_ACCEPT_RA_MIN_LFT,
                 DEFAULT_ACCEPT_RA_MIN_LFT);
         mApfCounterPollingIntervalMs = mDependencies.getDeviceConfigPropertyInt(
@@ -1095,7 +1081,7 @@
                 DEFAULT_NUD_FAILURE_COUNT_WEEKLY_THRESHOLD);
 
         IpClientLinkObserver.Configuration config = new IpClientLinkObserver.Configuration(
-                mMinRdnssLifetimeSec, mPopulateLinkAddressLifetime);
+                mAcceptRaMinLft, mPopulateLinkAddressLifetime);
 
         mLinkObserver = new IpClientLinkObserver(
                 mContext, getHandler(),
@@ -1205,7 +1191,8 @@
         @Override
         public void setL2KeyAndGroupHint(String l2Key, String cluster) {
             enforceNetworkStackCallingPermission();
-            IpClient.this.setL2KeyAndCluster(l2Key, cluster);
+            // This method is not supported anymore. The caller should call
+            // #updateLayer2Information() instead.
         }
         @Override
         public void setTcpBufferSizes(String tcpBufferSizes) {
@@ -1399,18 +1386,6 @@
     }
 
     /**
-     * Set the L2 key and cluster for storing info into the memory store.
-     *
-     * This method is only supported on Q devices. For R or above releases,
-     * caller should call #updateLayer2Information() instead.
-     */
-    public void setL2KeyAndCluster(String l2Key, String cluster) {
-        if (!ShimUtils.isReleaseOrDevelopmentApiAbove(Build.VERSION_CODES.Q)) {
-            sendMessage(CMD_UPDATE_L2KEY_CLUSTER, new Pair<>(l2Key, cluster));
-        }
-    }
-
-    /**
      * Set the HTTP Proxy configuration to use.
      *
      * This may be called, repeatedly, at any time before or after a call to
@@ -2748,7 +2723,7 @@
         apfConfig.multicastFilter = mMulticastFiltering;
         // Get the Configuration for ApfFilter from Context
         // Resource settings were moved from ApfCapabilities APIs to NetworkStack resources in S
-        if (ShimUtils.isReleaseOrDevelopmentApiAbove(Build.VERSION_CODES.R)) {
+        if (ShimUtils.isAtLeastS()) {
             final Resources res = mContext.getResources();
             apfConfig.ieee802_3Filter = res.getBoolean(R.bool.config_apfDrop802_3Frames);
             apfConfig.ethTypeBlackList = res.getIntArray(R.array.config_apfEthTypeDenyList);
@@ -2757,7 +2732,9 @@
             apfConfig.ethTypeBlackList = ApfCapabilities.getApfEtherTypeBlackList();
         }
 
-        apfConfig.minRdnssLifetimeSec = mMinRdnssLifetimeSec;
+        // The RDNSS option is not processed by the kernel, so lifetime filtering
+        // can occur independent of kernel support for accept_ra_min_lft.
+        apfConfig.minRdnssLifetimeSec = mAcceptRaMinLft;
         // Check the feature flag first before reading IPv6 sysctl, which can prevent from
         // triggering a potential kernel bug about the sysctl.
         // TODO: add unit test to check if the setIpv6Sysctl() is called or not.
@@ -2848,13 +2825,6 @@
                     handleLinkPropertiesUpdate(NO_CALLBACKS);
                     break;
 
-                case CMD_UPDATE_L2KEY_CLUSTER: {
-                    final Pair<String, String> args = (Pair<String, String>) msg.obj;
-                    mL2Key = args.first;
-                    mCluster = args.second;
-                    break;
-                }
-
                 case CMD_SET_MULTICAST_FILTER:
                     mMulticastFiltering = (boolean) msg.obj;
                     break;
@@ -3212,20 +3182,6 @@
                     transitionToStoppingState(DisconnectCode.forNumber(msg.arg1));
                     break;
 
-                case CMD_UPDATE_L2KEY_CLUSTER: {
-                    final Pair<String, String> args = (Pair<String, String>) msg.obj;
-                    mL2Key = args.first;
-                    mCluster = args.second;
-                    // TODO : attributes should be saved to the memory store with
-                    // these new values if they differ from the previous ones.
-                    // If the state machine is in pure StartedState, then the values to input
-                    // are not known yet and should be updated when the LinkProperties are updated.
-                    // If the state machine is in RunningState (which is a child of StartedState)
-                    // then the next NUD check should be used to store the new values to avoid
-                    // inputting current values for what may be a different L3 network.
-                    break;
-                }
-
                 case CMD_UPDATE_L2INFORMATION:
                     handleUpdateL2Information((Layer2InformationParcelable) msg.obj);
                     break;
diff --git a/src/com/android/server/NetworkStackService.java b/src/com/android/server/NetworkStackService.java
index 76b5e38..686a399 100644
--- a/src/com/android/server/NetworkStackService.java
+++ b/src/com/android/server/NetworkStackService.java
@@ -53,7 +53,6 @@
 import android.net.shared.PrivateDnsConfig;
 import android.net.util.RawPacketTracker;
 import android.net.util.RawSocketUtils;
-import android.os.Build;
 import android.os.HandlerThread;
 import android.os.IBinder;
 import android.os.Looper;
@@ -74,7 +73,6 @@
 import com.android.net.module.util.SharedLog;
 import com.android.networkstack.NetworkStackNotifier;
 import com.android.networkstack.R;
-import com.android.networkstack.apishim.common.ShimUtils;
 import com.android.networkstack.ipmemorystore.IpMemoryStoreService;
 import com.android.server.connectivity.NetworkMonitor;
 import com.android.server.util.PermissionUtil;
@@ -208,7 +206,6 @@
         @GuardedBy("mIpClients")
         private final ArrayList<WeakReference<IpClient>> mIpClients = new ArrayList<>();
         private final IpMemoryStoreService mIpMemoryStoreService;
-        @Nullable
         private final NetworkStackNotifier mNotifier;
 
         private static final int MAX_VALIDATION_LOGS = 10;
@@ -303,15 +300,10 @@
             mNetd = INetd.Stub.asInterface(
                     (IBinder) context.getSystemService(Context.NETD_SERVICE));
             mIpMemoryStoreService = mDeps.makeIpMemoryStoreService(context);
-            // NetworkStackNotifier only shows notifications relevant for API level > Q
-            if (ShimUtils.isReleaseOrDevelopmentApiAbove(Build.VERSION_CODES.Q)) {
-                final HandlerThread notifierThread = new HandlerThread(
-                        NetworkStackNotifier.class.getSimpleName());
-                notifierThread.start();
-                mNotifier = mDeps.makeNotifier(context, notifierThread.getLooper());
-            } else {
-                mNotifier = null;
-            }
+            final HandlerThread notifierThread = new HandlerThread(
+                    NetworkStackNotifier.class.getSimpleName());
+            notifierThread.start();
+            mNotifier = mDeps.makeNotifier(context, notifierThread.getLooper());
 
             int netdVersion;
             String netdHash;
@@ -730,11 +722,6 @@
          * Dump version information of the module and detected system version.
          */
         private void dumpVersion(@NonNull PrintWriter fout) {
-            if (!ShimUtils.isReleaseOrDevelopmentApiAbove(Build.VERSION_CODES.Q)) {
-                dumpVersionNumberOnly(fout);
-                return;
-            }
-
             fout.println("LocalInterface:" + this.VERSION + ":" + this.HASH);
             synchronized (mAidlVersions) {
                 // Sort versions for deterministic order in output
diff --git a/src/com/android/server/connectivity/NetworkMonitor.java b/src/com/android/server/connectivity/NetworkMonitor.java
index 1a36f25..659e911 100755
--- a/src/com/android/server/connectivity/NetworkMonitor.java
+++ b/src/com/android/server/connectivity/NetworkMonitor.java
@@ -125,7 +125,6 @@
 import android.net.util.Stopwatch;
 import android.net.wifi.WifiInfo;
 import android.net.wifi.WifiManager;
-import android.os.Build;
 import android.os.Bundle;
 import android.os.CancellationSignal;
 import android.os.Message;
@@ -476,7 +475,6 @@
     private final TelephonyManager mTelephonyManager;
     private final WifiManager mWifiManager;
     private final ConnectivityManager mCm;
-    @Nullable
     private final NetworkStackNotifier mNotifier;
     private final IpConnectivityLog mMetricsLog;
     private final Dependencies mDependencies;
@@ -1439,7 +1437,7 @@
                     final CaptivePortalProbeResult probeRes = mLastPortalProbeResult;
                     // Use redirect URL from AP if exists.
                     final String portalUrl =
-                            (useRedirectUrlForPortal() && makeURL(probeRes.redirectUrl) != null)
+                            (makeURL(probeRes.redirectUrl) != null)
                             ? probeRes.redirectUrl : probeRes.detectUrl;
                     appExtras.putString(EXTRA_CAPTIVE_PORTAL_URL, portalUrl);
                     if (probeRes.probeSpec != null) {
@@ -1448,9 +1446,7 @@
                     }
                     appExtras.putString(ConnectivityManager.EXTRA_CAPTIVE_PORTAL_USER_AGENT,
                             mCaptivePortalUserAgent);
-                    if (mNotifier != null) {
-                        mNotifier.notifyCaptivePortalValidationPending(network);
-                    }
+                    mNotifier.notifyCaptivePortalValidationPending(network);
                     mCm.startCaptivePortalApp(network, appExtras);
                     return HANDLED;
                 default:
@@ -1458,12 +1454,6 @@
             }
         }
 
-        private boolean useRedirectUrlForPortal() {
-            // It must match the conditions in CaptivePortalLogin in which the redirect URL is not
-            // used to validate that the portal is gone.
-            return ShimUtils.isReleaseOrDevelopmentApiAbove(Build.VERSION_CODES.Q);
-        }
-
         @Override
         public void exit() {
             if (mLaunchCaptivePortalAppBroadcastReceiver != null) {
diff --git a/tests/integration/common/android/net/ip/IpClientIntegrationTestCommon.java b/tests/integration/common/android/net/ip/IpClientIntegrationTestCommon.java
index 469a944..ff402dc 100644
--- a/tests/integration/common/android/net/ip/IpClientIntegrationTestCommon.java
+++ b/tests/integration/common/android/net/ip/IpClientIntegrationTestCommon.java
@@ -43,7 +43,6 @@
 import static android.net.ip.IpClient.CONFIG_APF_COUNTER_POLLING_INTERVAL_SECS;
 import static android.net.ip.IpClient.CONFIG_NUD_FAILURE_COUNT_DAILY_THRESHOLD;
 import static android.net.ip.IpClient.CONFIG_NUD_FAILURE_COUNT_WEEKLY_THRESHOLD;
-import static android.net.ip.IpClient.DEFAULT_ACCEPT_RA_MIN_LFT;
 import static android.net.ip.IpClient.DEFAULT_APF_COUNTER_POLLING_INTERVAL_SECS;
 import static android.net.ip.IpClient.DEFAULT_NUD_FAILURE_COUNT_DAILY_THRESHOLD;
 import static android.net.ip.IpClient.DEFAULT_NUD_FAILURE_COUNT_WEEKLY_THRESHOLD;
@@ -195,7 +194,6 @@
 import android.os.PowerManager;
 import android.os.RemoteException;
 import android.os.SystemClock;
-import android.os.SystemProperties;
 import android.provider.Settings;
 import android.stats.connectivity.NudEventType;
 import android.system.ErrnoException;
@@ -230,8 +228,6 @@
 import com.android.net.module.util.structs.RdnssOption;
 import com.android.networkstack.R;
 import com.android.networkstack.apishim.CaptivePortalDataShimImpl;
-import com.android.networkstack.apishim.ConstantsShim;
-import com.android.networkstack.apishim.common.ShimUtils;
 import com.android.networkstack.ipmemorystore.IpMemoryStoreService;
 import com.android.networkstack.metrics.IpProvisioningMetrics;
 import com.android.networkstack.metrics.IpReachabilityMonitorMetrics;
@@ -854,7 +850,6 @@
             return null;
         }).when(mIpMemoryStore).retrieveNetworkEventCount(eq(TEST_CLUSTER), any(), any(), any());
 
-        setDeviceConfigProperty(IpClient.CONFIG_MIN_RDNSS_LIFETIME, 67);
         setDeviceConfigProperty(DhcpClient.DHCP_RESTART_CONFIG_DELAY, 10);
         setDeviceConfigProperty(DhcpClient.ARP_FIRST_PROBE_DELAY_MS, 10);
         setDeviceConfigProperty(DhcpClient.ARP_PROBE_MIN_MS, 10);
@@ -872,7 +867,7 @@
 
         // Set the minimal RA lifetime value, any RA section with liftime below this value will be
         // ignored.
-        setDeviceConfigProperty(CONFIG_ACCEPT_RA_MIN_LFT, DEFAULT_ACCEPT_RA_MIN_LFT);
+        setDeviceConfigProperty(CONFIG_ACCEPT_RA_MIN_LFT, 67);
 
         // Set the polling interval to update APF data snapshot.
         setDeviceConfigProperty(CONFIG_APF_COUNTER_POLLING_INTERVAL_SECS,
@@ -1303,23 +1298,13 @@
             final List<DhcpPacket> packetList) throws Exception {
         for (DhcpPacket packet : packetList) {
             if (!expectSendHostname || hostname == null) {
-                assertNoHostname(packet.getHostname());
+                assertNull(packet.getHostname());
             } else {
                 assertEquals(hostnameAfterTransliteration, packet.getHostname());
             }
         }
     }
 
-    private void assertNoHostname(String hostname) {
-        if (ShimUtils.isAtLeastR()) {
-            assertNull(hostname);
-        } else {
-            // Until Q, if no hostname is set, the device falls back to the hostname set via
-            // system property, to avoid breaking Q devices already launched with that setup.
-            assertEquals(SystemProperties.get("net.hostname"), hostname);
-        }
-    }
-
     // Helper method to complete DHCP 2-way or 4-way handshake
     private List<DhcpPacket> performDhcpHandshake(final boolean isSuccessLease,
             final Integer leaseTimeSec, final boolean shouldReplyRapidCommitAck, final int mtu,
@@ -1770,7 +1755,7 @@
         assertIpMemoryStoreNetworkAttributes(TEST_LEASE_DURATION_S, currentTime, TEST_DEFAULT_MTU);
     }
 
-    @Test @IgnoreUpTo(Build.VERSION_CODES.Q)
+    @Test
     public void testRollbackFromRapidCommitOption() throws Exception {
         startIpClientProvisioning(true /* isDhcpRapidCommitEnabled */,
                 false /* isPreConnectionEnabled */,
@@ -1856,10 +1841,8 @@
         assertTrue(packet instanceof DhcpDiscoverPacket);
     }
 
-    @Test @IgnoreUpTo(Build.VERSION_CODES.Q)
+    @Test
     public void testDhcpServerInLinkProperties() throws Exception {
-        assumeTrue(ConstantsShim.VERSION > Build.VERSION_CODES.Q);
-
         performDhcpHandshake();
         ArgumentCaptor<LinkProperties> captor = ArgumentCaptor.forClass(LinkProperties.class);
         verify(mCb, timeout(TEST_TIMEOUT_MS)).onProvisioningSuccess(captor.capture());
@@ -2267,13 +2250,13 @@
 
         LinkProperties lp = doIpv6OnlyProvisioning(inOrder, ra);
 
-        // Expect that DNS servers with lifetimes below CONFIG_MIN_RDNSS_LIFETIME are not accepted.
+        // Expect that DNS servers with lifetimes below CONFIG_ACCEPT_RA_MIN_LFT are not accepted.
         assertNotNull(lp);
         assertEquals(1, lp.getDnsServers().size());
         assertTrue(lp.getDnsServers().contains(InetAddress.getByName(dnsServer)));
 
         // If the RDNSS lifetime is above the minimum, the DNS server is accepted.
-        rdnss1 = buildRdnssOption(68, lowlifeDnsServer);
+        rdnss1 = buildRdnssOption(67, lowlifeDnsServer);
         ra = buildRaPacket(pio, rdnss1, rdnss2);
         mPacketReader.sendResponse(ra);
         inOrder.verify(mCb, timeout(TEST_TIMEOUT_MS)).onLinkPropertiesChange(captor.capture());
@@ -2338,11 +2321,9 @@
 
     }
 
-    @Test @IgnoreUpTo(Build.VERSION_CODES.Q)
+    @Test
     @SignatureRequiredTest(reason = "TODO: evaluate whether signature perms are required")
     public void testPref64Option() throws Exception {
-        assumeTrue(ConstantsShim.VERSION > Build.VERSION_CODES.Q);
-
         ProvisioningConfiguration config = new ProvisioningConfiguration.Builder()
                 .withoutIpReachabilityMonitor()
                 .withoutIPv4()
@@ -2815,8 +2796,6 @@
                 argThat(lp -> lp.getMtu() == testMtu));
 
         // Ensure that the URL was set as expected in the callbacks.
-        // Can't verify the URL up to Q as there is no such attribute in LinkProperties.
-        if (!ShimUtils.isAtLeastR()) return null;
         verify(mCb, atLeastOnce()).onLinkPropertiesChange(captor.capture());
         final LinkProperties expectedLp = captor.getAllValues().stream().findFirst().get();
         assertNotNull(expectedLp);
diff --git a/tests/unit/src/android/net/ip/IpClientTest.java b/tests/unit/src/android/net/ip/IpClientTest.java
index 3fc843e..2fb0a7f 100644
--- a/tests/unit/src/android/net/ip/IpClientTest.java
+++ b/tests/unit/src/android/net/ip/IpClientTest.java
@@ -531,19 +531,20 @@
         final IpClient ipc = makeIpClient(iface);
         final String l2Key = TEST_L2KEY;
         final String cluster = TEST_CLUSTER;
+        final MacAddress bssid = MacAddress.fromString(TEST_BSSID);
 
         ProvisioningConfiguration config = new ProvisioningConfiguration.Builder()
                 .withoutIPv4()
                 .withoutIpReachabilityMonitor()
                 .withInitialConfiguration(
                         conf(links(TEST_LOCAL_ADDRESSES), prefixes(TEST_PREFIXES), ips()))
+                .withLayer2Information(new Layer2Information(l2Key, cluster, bssid))
                 .build();
 
         ipc.startProvisioning(config);
         verify(mCb, timeout(TEST_TIMEOUT_MS).times(1)).setNeighborDiscoveryOffload(true);
         verify(mCb, timeout(TEST_TIMEOUT_MS).times(1)).setFallbackMulticastFilter(false);
         verify(mCb, never()).onProvisioningFailure(any());
-        ipc.setL2KeyAndCluster(l2Key, cluster);
 
         for (String addr : TEST_LOCAL_ADDRESSES) {
             String[] parts = addr.split("/");