diff --git a/packages/Tethering/Android.bp b/packages/Tethering/Android.bp
index 596f62f..e79986c 100644
--- a/packages/Tethering/Android.bp
+++ b/packages/Tethering/Android.bp
@@ -20,7 +20,7 @@
     srcs: [
         "src/**/*.java",
         ":framework-tethering-shared-srcs",
-        ":net-module-utils-srcs",
+        ":tethering-module-utils-srcs",
         ":services-tethering-shared-srcs",
     ],
     static_libs: [
diff --git a/packages/Tethering/src/android/net/ip/IpServer.java b/packages/Tethering/src/android/net/ip/IpServer.java
index abfb33c..cf8769e 100644
--- a/packages/Tethering/src/android/net/ip/IpServer.java
+++ b/packages/Tethering/src/android/net/ip/IpServer.java
@@ -28,7 +28,6 @@
 import android.net.INetd;
 import android.net.INetworkStackStatusCallback;
 import android.net.INetworkStatsService;
-import android.net.InterfaceConfiguration;
 import android.net.IpPrefix;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
@@ -38,11 +37,11 @@
 import android.net.dhcp.DhcpServingParamsParcelExt;
 import android.net.dhcp.IDhcpServer;
 import android.net.ip.RouterAdvertisementDaemon.RaParams;
+import android.net.shared.NetdUtils;
+import android.net.shared.RouteUtils;
 import android.net.util.InterfaceParams;
 import android.net.util.InterfaceSet;
-import android.net.util.NetdService;
 import android.net.util.SharedLog;
-import android.os.INetworkManagementService;
 import android.os.Looper;
 import android.os.Message;
 import android.os.RemoteException;
@@ -144,10 +143,6 @@
             return InterfaceParams.getByName(ifName);
         }
 
-        public INetd getNetdService() {
-            return NetdService.getInstance();
-        }
-
         /** Create a DhcpServer instance to be used by IpServer. */
         public abstract void makeDhcpServer(String ifName, DhcpServingParamsParcel params,
                 DhcpServerCallbacks cb);
@@ -180,7 +175,6 @@
     private final State mUnavailableState;
 
     private final SharedLog mLog;
-    private final INetworkManagementService mNMService;
     private final INetd mNetd;
     private final INetworkStatsService mStatsService;
     private final Callback mCallback;
@@ -210,15 +204,15 @@
     private int mDhcpServerStartIndex = 0;
     private IDhcpServer mDhcpServer;
     private RaParams mLastRaParams;
+    private LinkAddress mIpv4Address;
 
     public IpServer(
             String ifaceName, Looper looper, int interfaceType, SharedLog log,
-            INetworkManagementService nMService, INetworkStatsService statsService,
-            Callback callback, boolean usingLegacyDhcp, Dependencies deps) {
+            INetd netd, INetworkStatsService statsService, Callback callback,
+            boolean usingLegacyDhcp, Dependencies deps) {
         super(ifaceName, looper);
         mLog = log.forSubComponent(ifaceName);
-        mNMService = nMService;
-        mNetd = deps.getNetdService();
+        mNetd = netd;
         mStatsService = statsService;
         mCallback = callback;
         mInterfaceCtrl = new InterfaceController(ifaceName, mNetd, mLog);
@@ -347,7 +341,7 @@
                         }
                     });
                 } catch (RemoteException e) {
-                    e.rethrowFromSystemServer();
+                    throw new IllegalStateException(e);
                 }
             });
         }
@@ -395,7 +389,8 @@
                 });
                 mDhcpServer = null;
             } catch (RemoteException e) {
-                e.rethrowFromSystemServer();
+                mLog.e("Error stopping DHCP", e);
+                // Not much more we can do here
             }
         }
     }
@@ -414,85 +409,69 @@
         // NOTE: All of configureIPv4() will be refactored out of existence
         // into calls to InterfaceController, shared with startIPv4().
         mInterfaceCtrl.clearIPv4Address();
+        mIpv4Address = null;
     }
 
-    // TODO: Refactor this in terms of calls to InterfaceController.
     private boolean configureIPv4(boolean enabled) {
         if (VDBG) Log.d(TAG, "configureIPv4(" + enabled + ")");
 
         // TODO: Replace this hard-coded information with dynamically selected
         // config passed down to us by a higher layer IP-coordinating element.
-        String ipAsString = null;
+        final Inet4Address srvAddr;
         int prefixLen = 0;
-        if (mInterfaceType == ConnectivityManager.TETHERING_USB) {
-            ipAsString = USB_NEAR_IFACE_ADDR;
-            prefixLen = USB_PREFIX_LENGTH;
-        } else if (mInterfaceType == ConnectivityManager.TETHERING_WIFI) {
-            ipAsString = getRandomWifiIPv4Address();
-            prefixLen = WIFI_HOST_IFACE_PREFIX_LENGTH;
-        } else if (mInterfaceType == ConnectivityManager.TETHERING_WIFI_P2P) {
-            ipAsString = WIFI_P2P_IFACE_ADDR;
-            prefixLen = WIFI_P2P_IFACE_PREFIX_LENGTH;
-        } else {
-            // BT configures the interface elsewhere: only start DHCP.
-            final Inet4Address srvAddr = (Inet4Address) parseNumericAddress(BLUETOOTH_IFACE_ADDR);
-            return configureDhcp(enabled, srvAddr, BLUETOOTH_DHCP_PREFIX_LENGTH);
+        try {
+            if (mInterfaceType == ConnectivityManager.TETHERING_USB) {
+                srvAddr = (Inet4Address) parseNumericAddress(USB_NEAR_IFACE_ADDR);
+                prefixLen = USB_PREFIX_LENGTH;
+            } else if (mInterfaceType == ConnectivityManager.TETHERING_WIFI) {
+                srvAddr = (Inet4Address) parseNumericAddress(getRandomWifiIPv4Address());
+                prefixLen = WIFI_HOST_IFACE_PREFIX_LENGTH;
+            } else if (mInterfaceType == ConnectivityManager.TETHERING_WIFI_P2P) {
+                srvAddr = (Inet4Address) parseNumericAddress(WIFI_P2P_IFACE_ADDR);
+                prefixLen = WIFI_P2P_IFACE_PREFIX_LENGTH;
+            } else {
+                // BT configures the interface elsewhere: only start DHCP.
+                // TODO: make all tethering types behave the same way, and delete the bluetooth
+                // code that calls into NetworkManagementService directly.
+                srvAddr = (Inet4Address) parseNumericAddress(BLUETOOTH_IFACE_ADDR);
+                mIpv4Address = new LinkAddress(srvAddr, BLUETOOTH_DHCP_PREFIX_LENGTH);
+                return configureDhcp(enabled, srvAddr, BLUETOOTH_DHCP_PREFIX_LENGTH);
+            }
+            mIpv4Address = new LinkAddress(srvAddr, prefixLen);
+        } catch (IllegalArgumentException e) {
+            mLog.e("Error selecting ipv4 address", e);
+            if (!enabled) stopDhcp();
+            return false;
         }
 
-        final LinkAddress linkAddr;
-        try {
-            final InterfaceConfiguration ifcg = mNMService.getInterfaceConfig(mIfaceName);
-            if (ifcg == null) {
-                mLog.e("Received null interface config");
-                return false;
-            }
+        final Boolean setIfaceUp;
+        if (mInterfaceType == ConnectivityManager.TETHERING_WIFI) {
+            // The WiFi stack has ownership of the interface up/down state.
+            // It is unclear whether the Bluetooth or USB stacks will manage their own
+            // state.
+            setIfaceUp = null;
+        } else {
+            setIfaceUp = enabled;
+        }
+        if (!mInterfaceCtrl.setInterfaceConfiguration(mIpv4Address, setIfaceUp)) {
+            mLog.e("Error configuring interface");
+            if (!enabled) stopDhcp();
+            return false;
+        }
 
-            InetAddress addr = parseNumericAddress(ipAsString);
-            linkAddr = new LinkAddress(addr, prefixLen);
-            ifcg.setLinkAddress(linkAddr);
-            if (mInterfaceType == ConnectivityManager.TETHERING_WIFI) {
-                // The WiFi stack has ownership of the interface up/down state.
-                // It is unclear whether the Bluetooth or USB stacks will manage their own
-                // state.
-                ifcg.ignoreInterfaceUpDownStatus();
-            } else {
-                if (enabled) {
-                    ifcg.setInterfaceUp();
-                } else {
-                    ifcg.setInterfaceDown();
-                }
-            }
-            ifcg.clearFlag("running");
-
-            // TODO: this may throw if the interface is already gone. Do proper handling and
-            // simplify the DHCP server start/stop.
-            mNMService.setInterfaceConfig(mIfaceName, ifcg);
-
-            if (!configureDhcp(enabled, (Inet4Address) addr, prefixLen)) {
-                return false;
-            }
-        } catch (Exception e) {
-            mLog.e("Error configuring interface " + e);
-            if (!enabled) {
-                try {
-                    // Calling stopDhcp several times is fine
-                    stopDhcp();
-                } catch (Exception dhcpError) {
-                    mLog.e("Error stopping DHCP", dhcpError);
-                }
-            }
+        if (!configureDhcp(enabled, srvAddr, prefixLen)) {
             return false;
         }
 
         // Directly-connected route.
-        final IpPrefix ipv4Prefix = new IpPrefix(linkAddr.getAddress(),
-                linkAddr.getPrefixLength());
+        final IpPrefix ipv4Prefix = new IpPrefix(mIpv4Address.getAddress(),
+                mIpv4Address.getPrefixLength());
         final RouteInfo route = new RouteInfo(ipv4Prefix, null, null, RTN_UNICAST);
         if (enabled) {
-            mLinkProperties.addLinkAddress(linkAddr);
+            mLinkProperties.addLinkAddress(mIpv4Address);
             mLinkProperties.addRoute(route);
         } else {
-            mLinkProperties.removeLinkAddress(linkAddr);
+            mLinkProperties.removeLinkAddress(mIpv4Address);
             mLinkProperties.removeRoute(route);
         }
         return true;
@@ -584,14 +563,12 @@
         if (!deprecatedPrefixes.isEmpty()) {
             final ArrayList<RouteInfo> toBeRemoved =
                     getLocalRoutesFor(mIfaceName, deprecatedPrefixes);
-            try {
-                final int removalFailures = mNMService.removeRoutesFromLocalNetwork(toBeRemoved);
-                if (removalFailures > 0) {
-                    mLog.e(String.format("Failed to remove %d IPv6 routes from local table.",
-                            removalFailures));
-                }
-            } catch (RemoteException e) {
-                mLog.e("Failed to remove IPv6 routes from local table: " + e);
+            // Remove routes from local network.
+            final int removalFailures = RouteUtils.removeRoutesFromLocalNetwork(
+                    mNetd, toBeRemoved);
+            if (removalFailures > 0) {
+                mLog.e(String.format("Failed to remove %d IPv6 routes from local table.",
+                        removalFailures));
             }
 
             for (RouteInfo route : toBeRemoved) mLinkProperties.removeRoute(route);
@@ -608,13 +585,18 @@
                 final ArrayList<RouteInfo> toBeAdded =
                         getLocalRoutesFor(mIfaceName, addedPrefixes);
                 try {
-                    // It's safe to call addInterfaceToLocalNetwork() even if
-                    // the interface is already in the local_network. Note also
-                    // that adding routes that already exist does not cause an
-                    // error (EEXIST is silently ignored).
-                    mNMService.addInterfaceToLocalNetwork(mIfaceName, toBeAdded);
-                } catch (Exception e) {
-                    mLog.e("Failed to add IPv6 routes to local table: " + e);
+                    // It's safe to call networkAddInterface() even if
+                    // the interface is already in the local_network.
+                    mNetd.networkAddInterface(INetd.LOCAL_NET_ID, mIfaceName);
+                    try {
+                        // Add routes from local network. Note that adding routes that
+                        // already exist does not cause an error (EEXIST is silently ignored).
+                        RouteUtils.addRoutesToLocalNetwork(mNetd, mIfaceName, toBeAdded);
+                    } catch (IllegalStateException e) {
+                        mLog.e("Failed to add IPv6 routes to local table: " + e);
+                    }
+                } catch (ServiceSpecificException | RemoteException e) {
+                    mLog.e("Failed to add " + mIfaceName + " to local table: ", e);
                 }
 
                 for (RouteInfo route : toBeAdded) mLinkProperties.addRoute(route);
@@ -762,8 +744,10 @@
             }
 
             try {
-                mNMService.tetherInterface(mIfaceName);
-            } catch (Exception e) {
+                final IpPrefix ipv4Prefix = new IpPrefix(mIpv4Address.getAddress(),
+                        mIpv4Address.getPrefixLength());
+                NetdUtils.tetherInterface(mNetd, mIfaceName, ipv4Prefix);
+            } catch (RemoteException | ServiceSpecificException e) {
                 mLog.e("Error Tethering: " + e);
                 mLastError = ConnectivityManager.TETHER_ERROR_TETHER_IFACE_ERROR;
                 return;
@@ -784,8 +768,8 @@
             stopIPv6();
 
             try {
-                mNMService.untetherInterface(mIfaceName);
-            } catch (Exception e) {
+                NetdUtils.untetherInterface(mNetd, mIfaceName);
+            } catch (RemoteException | ServiceSpecificException e) {
                 mLastError = ConnectivityManager.TETHER_ERROR_UNTETHER_IFACE_ERROR;
                 mLog.e("Failed to untether interface: " + e);
             }
@@ -901,17 +885,17 @@
                 // About to tear down NAT; gather remaining statistics.
                 mStatsService.forceUpdate();
             } catch (Exception e) {
-                if (VDBG) Log.e(TAG, "Exception in forceUpdate: " + e.toString());
+                mLog.e("Exception in forceUpdate: " + e.toString());
             }
             try {
-                mNMService.stopInterfaceForwarding(mIfaceName, upstreamIface);
-            } catch (Exception e) {
-                if (VDBG) Log.e(TAG, "Exception in removeInterfaceForward: " + e.toString());
+                mNetd.ipfwdRemoveInterfaceForward(mIfaceName, upstreamIface);
+            } catch (RemoteException | ServiceSpecificException e) {
+                mLog.e("Exception in ipfwdRemoveInterfaceForward: " + e.toString());
             }
             try {
-                mNMService.disableNat(mIfaceName, upstreamIface);
-            } catch (Exception e) {
-                if (VDBG) Log.e(TAG, "Exception in disableNat: " + e.toString());
+                mNetd.tetherRemoveForward(mIfaceName, upstreamIface);
+            } catch (RemoteException | ServiceSpecificException e) {
+                mLog.e("Exception in disableNat: " + e.toString());
             }
         }
 
@@ -947,10 +931,10 @@
 
                     for (String ifname : added) {
                         try {
-                            mNMService.enableNat(mIfaceName, ifname);
-                            mNMService.startInterfaceForwarding(mIfaceName, ifname);
-                        } catch (Exception e) {
-                            mLog.e("Exception enabling NAT: " + e);
+                            mNetd.tetherAddForward(mIfaceName, ifname);
+                            mNetd.ipfwdAddInterfaceForward(mIfaceName, ifname);
+                        } catch (RemoteException | ServiceSpecificException e) {
+                            mLog.e("Exception enabling NAT: " + e.toString());
                             cleanupUpstream();
                             mLastError = ConnectivityManager.TETHER_ERROR_ENABLE_NAT_ERROR;
                             transitionTo(mInitialState);
diff --git a/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java b/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
index 2c8858e..9b50a39 100644
--- a/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
+++ b/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
@@ -75,6 +75,7 @@
 import android.net.TetherStatesParcel;
 import android.net.TetheringConfigurationParcel;
 import android.net.ip.IpServer;
+import android.net.shared.NetdUtils;
 import android.net.util.BaseNetdUnsolicitedEventListener;
 import android.net.util.InterfaceSet;
 import android.net.util.PrefixUtils;
@@ -87,12 +88,12 @@
 import android.os.Binder;
 import android.os.Bundle;
 import android.os.Handler;
-import android.os.INetworkManagementService;
 import android.os.Looper;
 import android.os.Message;
 import android.os.RemoteCallbackList;
 import android.os.RemoteException;
 import android.os.ResultReceiver;
+import android.os.ServiceSpecificException;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.telephony.PhoneStateListener;
@@ -102,6 +103,9 @@
 import android.util.Log;
 import android.util.SparseArray;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.messages.nano.SystemMessageProto.SystemMessage;
 import com.android.internal.notification.SystemNotificationChannels;
@@ -139,6 +143,8 @@
     };
     private static final SparseArray<String> sMagicDecoderRing =
             MessageUtils.findMessageNames(sMessageClasses);
+    // Keep in sync with NETID_UNSET in system/netd/include/netid_client.h
+    private static final int NETID_UNSET = 0;
 
     private static class TetherState {
         public final IpServer ipServer;
@@ -172,8 +178,6 @@
     private final Context mContext;
     private final ArrayMap<String, TetherState> mTetherStates;
     private final BroadcastReceiver mStateReceiver;
-    // Stopship: replace mNMService before production.
-    private final INetworkManagementService mNMService;
     private final INetworkStatsService mStatsService;
     private final INetworkPolicyManager mPolicyManager;
     private final Looper mLooper;
@@ -210,7 +214,6 @@
         mLog.mark("Tethering.constructed");
         mDeps = deps;
         mContext = mDeps.getContext();
-        mNMService = mDeps.getINetworkManagementService();
         mStatsService = mDeps.getINetworkStatsService();
         mPolicyManager = mDeps.getINetworkPolicyManager();
         mNetd = mDeps.getINetd(mContext);
@@ -225,10 +228,9 @@
 
         mHandler = mTetherMasterSM.getHandler();
         mOffloadController = new OffloadController(mHandler,
-                mDeps.getOffloadHardwareInterface(mHandler, mLog),
-                mContext.getContentResolver(), mNMService,
-                mLog);
-        mUpstreamNetworkMonitor = deps.getUpstreamNetworkMonitor(mContext, mTetherMasterSM, mLog,
+                mDeps.getOffloadHardwareInterface(mHandler, mLog), mContext.getContentResolver(),
+                mDeps.getINetworkManagementService(), mLog);
+        mUpstreamNetworkMonitor = mDeps.getUpstreamNetworkMonitor(mContext, mTetherMasterSM, mLog,
                 TetherMasterSM.EVENT_UPSTREAM_CALLBACK);
         mForwardedDownstreams = new HashSet<>();
 
@@ -421,7 +423,6 @@
         }
     }
 
-
     void interfaceRemoved(String iface) {
         if (VDBG) Log.d(TAG, "interfaceRemoved " + iface);
         synchronized (mPublicSync) {
@@ -1022,8 +1023,8 @@
 
         String[] ifaces = null;
         try {
-            ifaces = mNMService.listInterfaces();
-        } catch (Exception e) {
+            ifaces = mNetd.interfaceGetList();
+        } catch (RemoteException | ServiceSpecificException e) {
             Log.e(TAG, "Error listing Interfaces", e);
             return;
         }
@@ -1282,25 +1283,25 @@
         protected boolean turnOnMasterTetherSettings() {
             final TetheringConfiguration cfg = mConfig;
             try {
-                mNMService.setIpForwardingEnabled(true);
-            } catch (Exception e) {
+                mNetd.ipfwdEnableForwarding(TAG);
+            } catch (RemoteException | ServiceSpecificException e) {
                 mLog.e(e);
                 transitionTo(mSetIpForwardingEnabledErrorState);
                 return false;
             }
+
             // TODO: Randomize DHCPv4 ranges, especially in hotspot mode.
             // Legacy DHCP server is disabled if passed an empty ranges array
             final String[] dhcpRanges = cfg.enableLegacyDhcpServer
-                    ? cfg.legacyDhcpRanges
-                    : new String[0];
+                    ? cfg.legacyDhcpRanges : new String[0];
             try {
-                // TODO: Find a more accurate method name (startDHCPv4()?).
-                mNMService.startTethering(dhcpRanges);
-            } catch (Exception e) {
+                NetdUtils.tetherStart(mNetd, true /** usingLegacyDnsProxy */, dhcpRanges);
+            } catch (RemoteException | ServiceSpecificException e) {
                 try {
-                    mNMService.stopTethering();
-                    mNMService.startTethering(dhcpRanges);
-                } catch (Exception ee) {
+                    // Stop and retry.
+                    mNetd.tetherStop();
+                    NetdUtils.tetherStart(mNetd, true /** usingLegacyDnsProxy */, dhcpRanges);
+                } catch (RemoteException | ServiceSpecificException ee) {
                     mLog.e(ee);
                     transitionTo(mStartTetheringErrorState);
                     return false;
@@ -1312,15 +1313,15 @@
 
         protected boolean turnOffMasterTetherSettings() {
             try {
-                mNMService.stopTethering();
-            } catch (Exception e) {
+                mNetd.tetherStop();
+            } catch (RemoteException | ServiceSpecificException e) {
                 mLog.e(e);
                 transitionTo(mStopTetheringErrorState);
                 return false;
             }
             try {
-                mNMService.setIpForwardingEnabled(false);
-            } catch (Exception e) {
+                mNetd.ipfwdDisableForwarding(TAG);
+            } catch (RemoteException | ServiceSpecificException e) {
                 mLog.e(e);
                 transitionTo(mSetIpForwardingDisabledErrorState);
                 return false;
@@ -1390,12 +1391,13 @@
                 // TODO: remove this invocation of NetworkUtils.makeStrings().
                 dnsServers = NetworkUtils.makeStrings(dnses);
             }
+            final int netId = (network != null) ? network.netId : NETID_UNSET;
             try {
-                mNMService.setDnsForwarders(network, dnsServers);
+                mNetd.tetherDnsSet(netId, dnsServers);
                 mLog.log(String.format(
                         "SET DNS forwarders: network=%s dnsServers=%s",
                         network, Arrays.toString(dnsServers)));
-            } catch (Exception e) {
+            } catch (RemoteException | ServiceSpecificException e) {
                 // TODO: Investigate how this can fail and what exactly
                 // happens if/when such failures occur.
                 mLog.e("setting DNS forwarders failed, " + e);
@@ -1698,8 +1700,8 @@
                 Log.e(TAG, "Error in startTethering");
                 notify(IpServer.CMD_START_TETHERING_ERROR);
                 try {
-                    mNMService.setIpForwardingEnabled(false);
-                } catch (Exception e) { }
+                    mNetd.ipfwdDisableForwarding(TAG);
+                } catch (RemoteException | ServiceSpecificException e) { }
             }
         }
 
@@ -1709,8 +1711,8 @@
                 Log.e(TAG, "Error in stopTethering");
                 notify(IpServer.CMD_STOP_TETHERING_ERROR);
                 try {
-                    mNMService.setIpForwardingEnabled(false);
-                } catch (Exception e) { }
+                    mNetd.ipfwdDisableForwarding(TAG);
+                } catch (RemoteException | ServiceSpecificException e) { }
             }
         }
 
@@ -1720,11 +1722,11 @@
                 Log.e(TAG, "Error in setDnsForwarders");
                 notify(IpServer.CMD_SET_DNS_FORWARDERS_ERROR);
                 try {
-                    mNMService.stopTethering();
-                } catch (Exception e) { }
+                    mNetd.tetherStop();
+                } catch (RemoteException | ServiceSpecificException e) { }
                 try {
-                    mNMService.setIpForwardingEnabled(false);
-                } catch (Exception e) { }
+                    mNetd.ipfwdDisableForwarding(TAG);
+                } catch (RemoteException | ServiceSpecificException e) { }
             }
         }
 
@@ -1884,7 +1886,7 @@
         }
     }
 
-    void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
+    void dump(@NonNull FileDescriptor fd, @NonNull PrintWriter writer, @Nullable String[] args) {
         // Binder.java closes the resource for us.
         @SuppressWarnings("resource")
         final IndentingPrintWriter pw = new IndentingPrintWriter(writer, "  ");
@@ -2065,7 +2067,7 @@
 
         mLog.log("adding TetheringInterfaceStateMachine for: " + iface);
         final TetherState tetherState = new TetherState(
-                new IpServer(iface, mLooper, interfaceType, mLog, mNMService, mStatsService,
+                new IpServer(iface, mLooper, interfaceType, mLog, mNetd, mStatsService,
                              makeControlCallback(), mConfig.enableLegacyDhcpServer,
                              mDeps.getIpServerDependencies()));
         mTetherStates.put(iface, tetherState);
diff --git a/packages/Tethering/tests/unit/src/android/net/ip/IpServerTest.java b/packages/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
index fd2f708..f4a6084 100644
--- a/packages/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
+++ b/packages/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
@@ -23,6 +23,7 @@
 import static android.net.ConnectivityManager.TETHER_ERROR_ENABLE_NAT_ERROR;
 import static android.net.ConnectivityManager.TETHER_ERROR_NO_ERROR;
 import static android.net.ConnectivityManager.TETHER_ERROR_TETHER_IFACE_ERROR;
+import static android.net.INetd.IF_STATE_UP;
 import static android.net.dhcp.IDhcpServer.STATUS_SUCCESS;
 import static android.net.ip.IpServer.STATE_AVAILABLE;
 import static android.net.ip.IpServer.STATE_LOCAL_ONLY;
@@ -52,7 +53,7 @@
 
 import android.net.INetd;
 import android.net.INetworkStatsService;
-import android.net.InterfaceConfiguration;
+import android.net.InterfaceConfigurationParcel;
 import android.net.IpPrefix;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
@@ -64,7 +65,6 @@
 import android.net.util.InterfaceParams;
 import android.net.util.InterfaceSet;
 import android.net.util.SharedLog;
-import android.os.INetworkManagementService;
 import android.os.RemoteException;
 import android.os.test.TestLooper;
 import android.text.TextUtils;
@@ -89,6 +89,8 @@
     private static final String IFACE_NAME = "testnet1";
     private static final String UPSTREAM_IFACE = "upstream0";
     private static final String UPSTREAM_IFACE2 = "upstream1";
+    private static final String BLUETOOTH_IFACE_ADDR = "192.168.42.1";
+    private static final int BLUETOOTH_DHCP_PREFIX_LENGTH = 24;
     private static final int DHCP_LEASE_TIME_SECS = 3600;
 
     private static final InterfaceParams TEST_IFACE_PARAMS = new InterfaceParams(
@@ -96,11 +98,9 @@
 
     private static final int MAKE_DHCPSERVER_TIMEOUT_MS = 1000;
 
-    @Mock private INetworkManagementService mNMService;
     @Mock private INetd mNetd;
     @Mock private INetworkStatsService mStatsService;
     @Mock private IpServer.Callback mCallback;
-    @Mock private InterfaceConfiguration mInterfaceConfiguration;
     @Mock private SharedLog mSharedLog;
     @Mock private IDhcpServer mDhcpServer;
     @Mock private RouterAdvertisementDaemon mRaDaemon;
@@ -112,6 +112,7 @@
     private final ArgumentCaptor<LinkProperties> mLinkPropertiesCaptor =
             ArgumentCaptor.forClass(LinkProperties.class);
     private IpServer mIpServer;
+    private InterfaceConfigurationParcel mInterfaceConfiguration;
 
     private void initStateMachine(int interfaceType) throws Exception {
         initStateMachine(interfaceType, false /* usingLegacyDhcp */);
@@ -131,17 +132,20 @@
         }).when(mDependencies).makeDhcpServer(any(), mDhcpParamsCaptor.capture(), any());
         when(mDependencies.getRouterAdvertisementDaemon(any())).thenReturn(mRaDaemon);
         when(mDependencies.getInterfaceParams(IFACE_NAME)).thenReturn(TEST_IFACE_PARAMS);
-        when(mDependencies.getNetdService()).thenReturn(mNetd);
-
+        mInterfaceConfiguration = new InterfaceConfigurationParcel();
+        mInterfaceConfiguration.flags = new String[0];
+        if (interfaceType == TETHERING_BLUETOOTH) {
+            mInterfaceConfiguration.ipv4Addr = BLUETOOTH_IFACE_ADDR;
+            mInterfaceConfiguration.prefixLength = BLUETOOTH_DHCP_PREFIX_LENGTH;
+        }
         mIpServer = new IpServer(
-                IFACE_NAME, mLooper.getLooper(), interfaceType, mSharedLog,
-                mNMService, mStatsService, mCallback, usingLegacyDhcp, mDependencies);
+                IFACE_NAME, mLooper.getLooper(), interfaceType, mSharedLog, mNetd, mStatsService,
+                mCallback, usingLegacyDhcp, mDependencies);
         mIpServer.start();
         // Starting the state machine always puts us in a consistent state and notifies
         // the rest of the world that we've changed from an unknown to available state.
         mLooper.dispatchAll();
-        reset(mNMService, mStatsService, mCallback);
-        when(mNMService.getInterfaceConfig(IFACE_NAME)).thenReturn(mInterfaceConfiguration);
+        reset(mNetd, mStatsService, mCallback);
 
         when(mRaDaemon.start()).thenReturn(true);
     }
@@ -158,8 +162,7 @@
         if (upstreamIface != null) {
             dispatchTetherConnectionChanged(upstreamIface);
         }
-        reset(mNMService, mStatsService, mCallback);
-        when(mNMService.getInterfaceConfig(IFACE_NAME)).thenReturn(mInterfaceConfiguration);
+        reset(mNetd, mStatsService, mCallback);
     }
 
     @Before public void setUp() throws Exception {
@@ -169,15 +172,14 @@
 
     @Test
     public void startsOutAvailable() {
-        mIpServer = new IpServer(IFACE_NAME, mLooper.getLooper(),
-                TETHERING_BLUETOOTH, mSharedLog, mNMService, mStatsService, mCallback,
-                false /* usingLegacyDhcp */, mDependencies);
+        mIpServer = new IpServer(IFACE_NAME, mLooper.getLooper(), TETHERING_BLUETOOTH, mSharedLog,
+                mNetd, mStatsService, mCallback, false /* usingLegacyDhcp */, mDependencies);
         mIpServer.start();
         mLooper.dispatchAll();
         verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_AVAILABLE, TETHER_ERROR_NO_ERROR);
         verify(mCallback).updateLinkProperties(eq(mIpServer), any(LinkProperties.class));
-        verifyNoMoreInteractions(mCallback, mNMService, mStatsService);
+        verifyNoMoreInteractions(mCallback, mNetd, mStatsService);
     }
 
     @Test
@@ -196,7 +198,7 @@
             // None of these commands should trigger us to request action from
             // the rest of the system.
             dispatchCommand(command);
-            verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+            verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
         }
     }
 
@@ -208,7 +210,7 @@
         verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_UNAVAILABLE, TETHER_ERROR_NO_ERROR);
         verify(mCallback).updateLinkProperties(eq(mIpServer), any(LinkProperties.class));
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
     }
 
     @Test
@@ -216,13 +218,17 @@
         initStateMachine(TETHERING_BLUETOOTH);
 
         dispatchCommand(IpServer.CMD_TETHER_REQUESTED, STATE_TETHERED);
-        InOrder inOrder = inOrder(mCallback, mNMService);
-        inOrder.verify(mNMService).tetherInterface(IFACE_NAME);
+        InOrder inOrder = inOrder(mCallback, mNetd);
+        inOrder.verify(mNetd).tetherInterfaceAdd(IFACE_NAME);
+        inOrder.verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        // One for ipv4 route, one for ipv6 link local route.
+        inOrder.verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(IFACE_NAME),
+                any(), any());
         inOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_TETHERED, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mCallback).updateLinkProperties(
                 eq(mIpServer), any(LinkProperties.class));
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
     }
 
     @Test
@@ -230,14 +236,16 @@
         initTetheredStateMachine(TETHERING_BLUETOOTH, null);
 
         dispatchCommand(IpServer.CMD_TETHER_UNREQUESTED);
-        InOrder inOrder = inOrder(mNMService, mNetd, mStatsService, mCallback);
-        inOrder.verify(mNMService).untetherInterface(IFACE_NAME);
+        InOrder inOrder = inOrder(mNetd, mStatsService, mCallback);
+        inOrder.verify(mNetd).tetherApplyDnsInterfaces();
+        inOrder.verify(mNetd).tetherInterfaceRemove(IFACE_NAME);
+        inOrder.verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
         inOrder.verify(mNetd).interfaceSetCfg(argThat(cfg -> IFACE_NAME.equals(cfg.ifName)));
         inOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_AVAILABLE, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mCallback).updateLinkProperties(
                 eq(mIpServer), any(LinkProperties.class));
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
     }
 
     @Test
@@ -245,16 +253,19 @@
         initStateMachine(TETHERING_USB);
 
         dispatchCommand(IpServer.CMD_TETHER_REQUESTED, STATE_TETHERED);
-        InOrder inOrder = inOrder(mCallback, mNMService);
-        inOrder.verify(mNMService).getInterfaceConfig(IFACE_NAME);
-        inOrder.verify(mNMService).setInterfaceConfig(IFACE_NAME, mInterfaceConfiguration);
-        inOrder.verify(mNMService).tetherInterface(IFACE_NAME);
+        InOrder inOrder = inOrder(mCallback, mNetd);
+        inOrder.verify(mNetd).interfaceSetCfg(argThat(cfg ->
+                  IFACE_NAME.equals(cfg.ifName) && assertContainsFlag(cfg.flags, IF_STATE_UP)));
+        inOrder.verify(mNetd).tetherInterfaceAdd(IFACE_NAME);
+        inOrder.verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        inOrder.verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(IFACE_NAME),
+                any(), any());
         inOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_TETHERED, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mCallback).updateLinkProperties(
                 eq(mIpServer), mLinkPropertiesCaptor.capture());
         assertIPv4AddressAndDirectlyConnectedRoute(mLinkPropertiesCaptor.getValue());
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
     }
 
     @Test
@@ -262,16 +273,19 @@
         initStateMachine(TETHERING_WIFI_P2P);
 
         dispatchCommand(IpServer.CMD_TETHER_REQUESTED, STATE_LOCAL_ONLY);
-        InOrder inOrder = inOrder(mCallback, mNMService);
-        inOrder.verify(mNMService).getInterfaceConfig(IFACE_NAME);
-        inOrder.verify(mNMService).setInterfaceConfig(IFACE_NAME, mInterfaceConfiguration);
-        inOrder.verify(mNMService).tetherInterface(IFACE_NAME);
+        InOrder inOrder = inOrder(mCallback, mNetd);
+        inOrder.verify(mNetd).interfaceSetCfg(argThat(cfg ->
+                  IFACE_NAME.equals(cfg.ifName) && assertContainsFlag(cfg.flags, IF_STATE_UP)));
+        inOrder.verify(mNetd).tetherInterfaceAdd(IFACE_NAME);
+        inOrder.verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        inOrder.verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(IFACE_NAME),
+                any(), any());
         inOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_LOCAL_ONLY, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mCallback).updateLinkProperties(
                 eq(mIpServer), mLinkPropertiesCaptor.capture());
         assertIPv4AddressAndDirectlyConnectedRoute(mLinkPropertiesCaptor.getValue());
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
     }
 
     @Test
@@ -281,10 +295,10 @@
         // Telling the state machine about its upstream interface triggers
         // a little more configuration.
         dispatchTetherConnectionChanged(UPSTREAM_IFACE);
-        InOrder inOrder = inOrder(mNMService);
-        inOrder.verify(mNMService).enableNat(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).startInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE);
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        InOrder inOrder = inOrder(mNetd);
+        inOrder.verify(mNetd).tetherAddForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).ipfwdAddInterfaceForward(IFACE_NAME, UPSTREAM_IFACE);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
     }
 
     @Test
@@ -292,49 +306,49 @@
         initTetheredStateMachine(TETHERING_BLUETOOTH, UPSTREAM_IFACE);
 
         dispatchTetherConnectionChanged(UPSTREAM_IFACE2);
-        InOrder inOrder = inOrder(mNMService, mStatsService);
+        InOrder inOrder = inOrder(mNetd, mStatsService);
         inOrder.verify(mStatsService).forceUpdate();
-        inOrder.verify(mNMService).stopInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).disableNat(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).enableNat(IFACE_NAME, UPSTREAM_IFACE2);
-        inOrder.verify(mNMService).startInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE2);
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        inOrder.verify(mNetd).ipfwdRemoveInterfaceForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).tetherRemoveForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).tetherAddForward(IFACE_NAME, UPSTREAM_IFACE2);
+        inOrder.verify(mNetd).ipfwdAddInterfaceForward(IFACE_NAME, UPSTREAM_IFACE2);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
     }
 
     @Test
     public void handlesChangingUpstreamNatFailure() throws Exception {
         initTetheredStateMachine(TETHERING_WIFI, UPSTREAM_IFACE);
 
-        doThrow(RemoteException.class).when(mNMService).enableNat(IFACE_NAME, UPSTREAM_IFACE2);
+        doThrow(RemoteException.class).when(mNetd).tetherAddForward(IFACE_NAME, UPSTREAM_IFACE2);
 
         dispatchTetherConnectionChanged(UPSTREAM_IFACE2);
-        InOrder inOrder = inOrder(mNMService, mStatsService);
+        InOrder inOrder = inOrder(mNetd, mStatsService);
         inOrder.verify(mStatsService).forceUpdate();
-        inOrder.verify(mNMService).stopInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).disableNat(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).enableNat(IFACE_NAME, UPSTREAM_IFACE2);
+        inOrder.verify(mNetd).ipfwdRemoveInterfaceForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).tetherRemoveForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).tetherAddForward(IFACE_NAME, UPSTREAM_IFACE2);
         inOrder.verify(mStatsService).forceUpdate();
-        inOrder.verify(mNMService).stopInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE2);
-        inOrder.verify(mNMService).disableNat(IFACE_NAME, UPSTREAM_IFACE2);
+        inOrder.verify(mNetd).ipfwdRemoveInterfaceForward(IFACE_NAME, UPSTREAM_IFACE2);
+        inOrder.verify(mNetd).tetherRemoveForward(IFACE_NAME, UPSTREAM_IFACE2);
     }
 
     @Test
     public void handlesChangingUpstreamInterfaceForwardingFailure() throws Exception {
         initTetheredStateMachine(TETHERING_WIFI, UPSTREAM_IFACE);
 
-        doThrow(RemoteException.class).when(mNMService).startInterfaceForwarding(
+        doThrow(RemoteException.class).when(mNetd).ipfwdAddInterfaceForward(
                 IFACE_NAME, UPSTREAM_IFACE2);
 
         dispatchTetherConnectionChanged(UPSTREAM_IFACE2);
-        InOrder inOrder = inOrder(mNMService, mStatsService);
+        InOrder inOrder = inOrder(mNetd, mStatsService);
         inOrder.verify(mStatsService).forceUpdate();
-        inOrder.verify(mNMService).stopInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).disableNat(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).enableNat(IFACE_NAME, UPSTREAM_IFACE2);
-        inOrder.verify(mNMService).startInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE2);
+        inOrder.verify(mNetd).ipfwdRemoveInterfaceForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).tetherRemoveForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).tetherAddForward(IFACE_NAME, UPSTREAM_IFACE2);
+        inOrder.verify(mNetd).ipfwdAddInterfaceForward(IFACE_NAME, UPSTREAM_IFACE2);
         inOrder.verify(mStatsService).forceUpdate();
-        inOrder.verify(mNMService).stopInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE2);
-        inOrder.verify(mNMService).disableNat(IFACE_NAME, UPSTREAM_IFACE2);
+        inOrder.verify(mNetd).ipfwdRemoveInterfaceForward(IFACE_NAME, UPSTREAM_IFACE2);
+        inOrder.verify(mNetd).tetherRemoveForward(IFACE_NAME, UPSTREAM_IFACE2);
     }
 
     @Test
@@ -342,17 +356,19 @@
         initTetheredStateMachine(TETHERING_BLUETOOTH, UPSTREAM_IFACE);
 
         dispatchCommand(IpServer.CMD_TETHER_UNREQUESTED);
-        InOrder inOrder = inOrder(mNMService, mNetd, mStatsService, mCallback);
+        InOrder inOrder = inOrder(mNetd, mStatsService, mCallback);
         inOrder.verify(mStatsService).forceUpdate();
-        inOrder.verify(mNMService).stopInterfaceForwarding(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).disableNat(IFACE_NAME, UPSTREAM_IFACE);
-        inOrder.verify(mNMService).untetherInterface(IFACE_NAME);
+        inOrder.verify(mNetd).ipfwdRemoveInterfaceForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).tetherRemoveForward(IFACE_NAME, UPSTREAM_IFACE);
+        inOrder.verify(mNetd).tetherApplyDnsInterfaces();
+        inOrder.verify(mNetd).tetherInterfaceRemove(IFACE_NAME);
+        inOrder.verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
         inOrder.verify(mNetd).interfaceSetCfg(argThat(cfg -> IFACE_NAME.equals(cfg.ifName)));
         inOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_AVAILABLE, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mCallback).updateLinkProperties(
                 eq(mIpServer), any(LinkProperties.class));
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
     }
 
     @Test
@@ -361,13 +377,14 @@
             initTetheredStateMachine(TETHERING_USB, null);
 
             if (shouldThrow) {
-                doThrow(RemoteException.class).when(mNMService).untetherInterface(IFACE_NAME);
+                doThrow(RemoteException.class).when(mNetd).tetherInterfaceRemove(IFACE_NAME);
             }
             dispatchCommand(IpServer.CMD_INTERFACE_DOWN);
-            InOrder usbTeardownOrder = inOrder(mNMService, mInterfaceConfiguration, mCallback);
-            usbTeardownOrder.verify(mInterfaceConfiguration).setInterfaceDown();
-            usbTeardownOrder.verify(mNMService).setInterfaceConfig(
-                    IFACE_NAME, mInterfaceConfiguration);
+            InOrder usbTeardownOrder = inOrder(mNetd, mCallback);
+            // Currently IpServer interfaceSetCfg twice to stop IPv4. One just set interface down
+            // Another one is set IPv4 to 0.0.0.0/0 as clearng ipv4 address.
+            usbTeardownOrder.verify(mNetd, times(2)).interfaceSetCfg(
+                    argThat(cfg -> IFACE_NAME.equals(cfg.ifName)));
             usbTeardownOrder.verify(mCallback).updateInterfaceState(
                     mIpServer, STATE_UNAVAILABLE, TETHER_ERROR_NO_ERROR);
             usbTeardownOrder.verify(mCallback).updateLinkProperties(
@@ -380,12 +397,15 @@
     public void usbShouldBeTornDownOnTetherError() throws Exception {
         initStateMachine(TETHERING_USB);
 
-        doThrow(RemoteException.class).when(mNMService).tetherInterface(IFACE_NAME);
+        doThrow(RemoteException.class).when(mNetd).tetherInterfaceAdd(IFACE_NAME);
         dispatchCommand(IpServer.CMD_TETHER_REQUESTED, STATE_TETHERED);
-        InOrder usbTeardownOrder = inOrder(mNMService, mInterfaceConfiguration, mCallback);
-        usbTeardownOrder.verify(mInterfaceConfiguration).setInterfaceDown();
-        usbTeardownOrder.verify(mNMService).setInterfaceConfig(
-                IFACE_NAME, mInterfaceConfiguration);
+        InOrder usbTeardownOrder = inOrder(mNetd, mCallback);
+        usbTeardownOrder.verify(mNetd).interfaceSetCfg(
+                argThat(cfg -> IFACE_NAME.equals(cfg.ifName)));
+        usbTeardownOrder.verify(mNetd).tetherInterfaceAdd(IFACE_NAME);
+
+        usbTeardownOrder.verify(mNetd, times(2)).interfaceSetCfg(
+                argThat(cfg -> IFACE_NAME.equals(cfg.ifName)));
         usbTeardownOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_AVAILABLE, TETHER_ERROR_TETHER_IFACE_ERROR);
         usbTeardownOrder.verify(mCallback).updateLinkProperties(
@@ -397,11 +417,13 @@
     public void shouldTearDownUsbOnUpstreamError() throws Exception {
         initTetheredStateMachine(TETHERING_USB, null);
 
-        doThrow(RemoteException.class).when(mNMService).enableNat(anyString(), anyString());
+        doThrow(RemoteException.class).when(mNetd).tetherAddForward(anyString(), anyString());
         dispatchTetherConnectionChanged(UPSTREAM_IFACE);
-        InOrder usbTeardownOrder = inOrder(mNMService, mInterfaceConfiguration, mCallback);
-        usbTeardownOrder.verify(mInterfaceConfiguration).setInterfaceDown();
-        usbTeardownOrder.verify(mNMService).setInterfaceConfig(IFACE_NAME, mInterfaceConfiguration);
+        InOrder usbTeardownOrder = inOrder(mNetd, mCallback);
+        usbTeardownOrder.verify(mNetd).tetherAddForward(IFACE_NAME, UPSTREAM_IFACE);
+
+        usbTeardownOrder.verify(mNetd, times(2)).interfaceSetCfg(
+                argThat(cfg -> IFACE_NAME.equals(cfg.ifName)));
         usbTeardownOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_AVAILABLE, TETHER_ERROR_ENABLE_NAT_ERROR);
         usbTeardownOrder.verify(mCallback).updateLinkProperties(
@@ -413,11 +435,11 @@
     public void ignoresDuplicateUpstreamNotifications() throws Exception {
         initTetheredStateMachine(TETHERING_WIFI, UPSTREAM_IFACE);
 
-        verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+        verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
 
         for (int i = 0; i < 5; i++) {
             dispatchTetherConnectionChanged(UPSTREAM_IFACE);
-            verifyNoMoreInteractions(mNMService, mStatsService, mCallback);
+            verifyNoMoreInteractions(mNetd, mStatsService, mCallback);
         }
     }
 
@@ -525,4 +547,12 @@
         // never see an empty interface name in any LinkProperties update.
         assertFalse(TextUtils.isEmpty(lp.getInterfaceName()));
     }
+
+    private boolean assertContainsFlag(String[] flags, String match) {
+        for (String flag : flags) {
+            if (flag.equals(match)) return true;
+        }
+        fail("Missing flag: " + match);
+        return false;
+    }
 }
diff --git a/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java b/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
index 809f0e9..144631c 100644
--- a/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
+++ b/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
@@ -50,7 +50,6 @@
 import static org.mockito.Matchers.anyString;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.any;
-import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -74,7 +73,7 @@
 import android.net.INetworkStatsService;
 import android.net.ITetheringEventCallback;
 import android.net.InetAddresses;
-import android.net.InterfaceConfiguration;
+import android.net.InterfaceConfigurationParcel;
 import android.net.IpPrefix;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
@@ -147,6 +146,7 @@
     private static final String TEST_USB_IFNAME = "test_rndis0";
     private static final String TEST_WLAN_IFNAME = "test_wlan0";
     private static final String TEST_P2P_IFNAME = "test_p2p-p2p0-0";
+    private static final String TETHERING_NAME = "Tethering";
 
     private static final int DHCPSERVER_START_TIMEOUT_MS = 1000;
 
@@ -185,6 +185,7 @@
     private BroadcastReceiver mBroadcastReceiver;
     private Tethering mTethering;
     private PhoneStateListener mPhoneStateListener;
+    private InterfaceConfigurationParcel mInterfaceConfiguration;
 
     private class TestContext extends BroadcastInterceptingContext {
         TestContext(Context base) {
@@ -248,11 +249,6 @@
         }
 
         @Override
-        public INetd getNetdService() {
-            return mNetd;
-        }
-
-        @Override
         public void makeDhcpServer(String ifName, DhcpServingParamsParcel params,
                 DhcpServerCallbacks cb) {
             new Thread(() -> {
@@ -429,11 +425,11 @@
                 .thenReturn(new int[0]);
         when(mResources.getBoolean(com.android.internal.R.bool.config_tether_upstream_automatic))
                 .thenReturn(false);
-        when(mNMService.listInterfaces())
+        when(mNetd.interfaceGetList())
                 .thenReturn(new String[] {
                         TEST_MOBILE_IFNAME, TEST_WLAN_IFNAME, TEST_USB_IFNAME, TEST_P2P_IFNAME});
-        when(mNMService.getInterfaceConfig(anyString()))
-                .thenReturn(new InterfaceConfiguration());
+        mInterfaceConfiguration = new InterfaceConfigurationParcel();
+        mInterfaceConfiguration.flags = new String[0];
         when(mRouterAdvertisementDaemon.start())
                 .thenReturn(true);
 
@@ -523,10 +519,11 @@
     }
 
     private void verifyInterfaceServingModeStarted(String ifname) throws Exception {
-        verify(mNMService, times(1)).getInterfaceConfig(ifname);
-        verify(mNMService, times(1))
-                .setInterfaceConfig(eq(ifname), any(InterfaceConfiguration.class));
-        verify(mNMService, times(1)).tetherInterface(ifname);
+        verify(mNetd, times(1)).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
+        verify(mNetd, times(1)).tetherInterfaceAdd(ifname);
+        verify(mNetd, times(1)).networkAddInterface(INetd.LOCAL_NET_ID, ifname);
+        verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(ifname),
+                anyString(), anyString());
     }
 
     private void verifyTetheringBroadcast(String ifname, String whichExtra) {
@@ -558,7 +555,7 @@
             verify(mWifiManager).updateInterfaceIpState(
                     TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
         }
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
         verifyNoMoreInteractions(mWifiManager);
     }
 
@@ -581,14 +578,14 @@
         prepareUsbTethering(upstreamState);
 
         // This should produce no activity of any kind.
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
 
         // Pretend we then receive USB configured broadcast.
         sendUsbBroadcast(true, true, true);
         mLooper.dispatchAll();
         // Now we should see the start of tethering mechanics (in this case:
         // tetherMatchingInterfaces() which starts by fetching all interfaces).
-        verify(mNMService, times(1)).listInterfaces();
+        verify(mNetd, times(1)).interfaceGetList();
 
         // UpstreamNetworkMonitor should receive selected upstream
         verify(mUpstreamNetworkMonitor, times(1)).selectPreferredUpstreamType(any());
@@ -618,9 +615,9 @@
 
         verifyInterfaceServingModeStarted(TEST_WLAN_IFNAME);
         verifyTetheringBroadcast(TEST_WLAN_IFNAME, EXTRA_AVAILABLE_TETHER);
-        verify(mNMService, times(1)).setIpForwardingEnabled(true);
-        verify(mNMService, times(1)).startTethering(any(String[].class));
-        verifyNoMoreInteractions(mNMService);
+        verify(mNetd, times(1)).ipfwdEnableForwarding(TETHERING_NAME);
+        verify(mNetd, times(1)).tetherStartWithConfiguration(any());
+        verifyNoMoreInteractions(mNetd);
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
         verify(mWifiManager).updateInterfaceIpState(
@@ -638,16 +635,16 @@
         mTethering.interfaceRemoved(TEST_WLAN_IFNAME);
         mLooper.dispatchAll();
 
-        verify(mNMService, times(1)).untetherInterface(TEST_WLAN_IFNAME);
-        // {g,s}etInterfaceConfig() called twice for enabling and disabling IPv4.
-        verify(mNMService, times(2)).getInterfaceConfig(TEST_WLAN_IFNAME);
-        verify(mNMService, times(2))
-                .setInterfaceConfig(eq(TEST_WLAN_IFNAME), any(InterfaceConfiguration.class));
-        verify(mNMService, times(1)).stopTethering();
-        verify(mNMService, times(1)).setIpForwardingEnabled(false);
+        verify(mNetd, times(1)).tetherApplyDnsInterfaces();
+        verify(mNetd, times(1)).tetherInterfaceRemove(TEST_WLAN_IFNAME);
+        verify(mNetd, times(1)).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+        // interfaceSetCfg() called once for enabling and twice disabling IPv4.
+        verify(mNetd, times(3)).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
+        verify(mNetd, times(1)).tetherStop();
+        verify(mNetd, times(1)).ipfwdDisableForwarding(TETHERING_NAME);
         verify(mWifiManager, times(3)).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
         verifyNoMoreInteractions(mWifiManager);
         // Asking for the last error after the per-interface state machine
         // has been reaped yields an unknown interface error.
@@ -684,8 +681,8 @@
         UpstreamNetworkState upstreamState = buildMobileIPv4UpstreamState();
         runUsbTethering(upstreamState);
 
-        verify(mNMService, times(1)).enableNat(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
-        verify(mNMService, times(1)).startInterfaceForwarding(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).tetherAddForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).ipfwdAddInterfaceForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
 
         sendIPv6TetherUpdates(upstreamState);
         verify(mRouterAdvertisementDaemon, never()).buildNewRa(any(), notNull());
@@ -708,8 +705,8 @@
         UpstreamNetworkState upstreamState = buildMobileIPv6UpstreamState();
         runUsbTethering(upstreamState);
 
-        verify(mNMService, times(1)).enableNat(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
-        verify(mNMService, times(1)).startInterfaceForwarding(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).tetherAddForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).ipfwdAddInterfaceForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
 
         sendIPv6TetherUpdates(upstreamState);
         verify(mRouterAdvertisementDaemon, times(1)).buildNewRa(any(), notNull());
@@ -721,8 +718,8 @@
         UpstreamNetworkState upstreamState = buildMobileDualStackUpstreamState();
         runUsbTethering(upstreamState);
 
-        verify(mNMService, times(1)).enableNat(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
-        verify(mNMService, times(1)).startInterfaceForwarding(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).tetherAddForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).ipfwdAddInterfaceForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
         verify(mRouterAdvertisementDaemon, times(1)).start();
         verify(mDhcpServer, timeout(DHCPSERVER_START_TIMEOUT_MS).times(1)).start(any());
 
@@ -736,12 +733,11 @@
         UpstreamNetworkState upstreamState = buildMobile464xlatUpstreamState();
         runUsbTethering(upstreamState);
 
-        verify(mNMService, times(1)).enableNat(TEST_USB_IFNAME, TEST_XLAT_MOBILE_IFNAME);
-        verify(mNMService, times(1)).enableNat(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).tetherAddForward(TEST_USB_IFNAME, TEST_XLAT_MOBILE_IFNAME);
+        verify(mNetd, times(1)).tetherAddForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
         verify(mDhcpServer, timeout(DHCPSERVER_START_TIMEOUT_MS).times(1)).start(any());
-        verify(mNMService, times(1)).startInterfaceForwarding(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
-        verify(mNMService, times(1)).startInterfaceForwarding(TEST_USB_IFNAME,
-                TEST_XLAT_MOBILE_IFNAME);
+        verify(mNetd, times(1)).ipfwdAddInterfaceForward(TEST_USB_IFNAME, TEST_XLAT_MOBILE_IFNAME);
+        verify(mNetd, times(1)).ipfwdAddInterfaceForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
 
         sendIPv6TetherUpdates(upstreamState);
         verify(mRouterAdvertisementDaemon, times(1)).buildNewRa(any(), notNull());
@@ -754,9 +750,9 @@
         UpstreamNetworkState upstreamState = buildMobileIPv6UpstreamState();
         runUsbTethering(upstreamState);
 
-        verify(mNMService, times(1)).enableNat(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).tetherAddForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
         verify(mDhcpServer, timeout(DHCPSERVER_START_TIMEOUT_MS).times(1)).start(any());
-        verify(mNMService, times(1)).startInterfaceForwarding(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).ipfwdAddInterfaceForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
 
         // Then 464xlat comes up
         upstreamState = buildMobile464xlatUpstreamState();
@@ -772,12 +768,11 @@
         mLooper.dispatchAll();
 
         // Forwarding is added for 464xlat
-        verify(mNMService, times(1)).enableNat(TEST_USB_IFNAME, TEST_XLAT_MOBILE_IFNAME);
-        verify(mNMService, times(1)).startInterfaceForwarding(TEST_USB_IFNAME,
-                TEST_XLAT_MOBILE_IFNAME);
+        verify(mNetd, times(1)).tetherAddForward(TEST_USB_IFNAME, TEST_XLAT_MOBILE_IFNAME);
+        verify(mNetd, times(1)).ipfwdAddInterfaceForward(TEST_USB_IFNAME, TEST_XLAT_MOBILE_IFNAME);
         // Forwarding was not re-added for v6 (still times(1))
-        verify(mNMService, times(1)).enableNat(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
-        verify(mNMService, times(1)).startInterfaceForwarding(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).tetherAddForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
+        verify(mNetd, times(1)).ipfwdAddInterfaceForward(TEST_USB_IFNAME, TEST_MOBILE_IFNAME);
         // DHCP not restarted on downstream (still times(1))
         verify(mDhcpServer, timeout(DHCPSERVER_START_TIMEOUT_MS).times(1)).start(any());
     }
@@ -820,7 +815,7 @@
         mLooper.dispatchAll();
         verify(mWifiManager, times(1)).startSoftAp(null);
         verifyNoMoreInteractions(mWifiManager);
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
 
         // Emulate externally-visible WifiManager effects, causing the
         // per-interface state machine to start up, and telling us that
@@ -833,7 +828,7 @@
         verifyTetheringBroadcast(TEST_WLAN_IFNAME, EXTRA_AVAILABLE_TETHER);
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
         verifyNoMoreInteractions(mWifiManager);
     }
 
@@ -847,7 +842,7 @@
         mLooper.dispatchAll();
         verify(mWifiManager, times(1)).startSoftAp(null);
         verifyNoMoreInteractions(mWifiManager);
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
 
         // Emulate externally-visible WifiManager effects, causing the
         // per-interface state machine to start up, and telling us that
@@ -858,9 +853,11 @@
 
         verifyInterfaceServingModeStarted(TEST_WLAN_IFNAME);
         verifyTetheringBroadcast(TEST_WLAN_IFNAME, EXTRA_AVAILABLE_TETHER);
-        verify(mNMService, times(1)).setIpForwardingEnabled(true);
-        verify(mNMService, times(1)).startTethering(any(String[].class));
-        verifyNoMoreInteractions(mNMService);
+        verify(mNetd, times(1)).ipfwdEnableForwarding(TETHERING_NAME);
+        verify(mNetd, times(1)).tetherStartWithConfiguration(any());
+        verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(TEST_WLAN_IFNAME),
+                anyString(), anyString());
+        verifyNoMoreInteractions(mNetd);
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
         verify(mWifiManager).updateInterfaceIpState(
@@ -878,8 +875,8 @@
         /////
         // We do not currently emulate any upstream being found.
         //
-        // This is why there are no calls to verify mNMService.enableNat() or
-        // mNMService.startInterfaceForwarding().
+        // This is why there are no calls to verify mNetd.tetherAddForward() or
+        // mNetd.ipfwdAddInterfaceForward().
         /////
 
         // Emulate pressing the WiFi tethering button.
@@ -887,7 +884,7 @@
         mLooper.dispatchAll();
         verify(mWifiManager, times(1)).stopSoftAp();
         verifyNoMoreInteractions(mWifiManager);
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
 
         // Emulate externally-visible WifiManager effects, when tethering mode
         // is being torn down.
@@ -895,16 +892,16 @@
         mTethering.interfaceRemoved(TEST_WLAN_IFNAME);
         mLooper.dispatchAll();
 
-        verify(mNMService, times(1)).untetherInterface(TEST_WLAN_IFNAME);
-        // {g,s}etInterfaceConfig() called twice for enabling and disabling IPv4.
-        verify(mNMService, atLeastOnce()).getInterfaceConfig(TEST_WLAN_IFNAME);
-        verify(mNMService, atLeastOnce())
-                .setInterfaceConfig(eq(TEST_WLAN_IFNAME), any(InterfaceConfiguration.class));
-        verify(mNMService, times(1)).stopTethering();
-        verify(mNMService, times(1)).setIpForwardingEnabled(false);
+        verify(mNetd, times(1)).tetherApplyDnsInterfaces();
+        verify(mNetd, times(1)).tetherInterfaceRemove(TEST_WLAN_IFNAME);
+        verify(mNetd, times(1)).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+        // interfaceSetCfg() called once for enabling and twice for disabling IPv4.
+        verify(mNetd, times(3)).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
+        verify(mNetd, times(1)).tetherStop();
+        verify(mNetd, times(1)).ipfwdDisableForwarding(TETHERING_NAME);
         verify(mWifiManager, times(3)).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
         verifyNoMoreInteractions(mWifiManager);
         // Asking for the last error after the per-interface state machine
         // has been reaped yields an unknown interface error.
@@ -915,14 +912,14 @@
     @Test
     public void failureEnablingIpForwarding() throws Exception {
         when(mWifiManager.startSoftAp(any(WifiConfiguration.class))).thenReturn(true);
-        doThrow(new RemoteException()).when(mNMService).setIpForwardingEnabled(true);
+        doThrow(new RemoteException()).when(mNetd).ipfwdEnableForwarding(TETHERING_NAME);
 
         // Emulate pressing the WiFi tethering button.
         mTethering.startTethering(TETHERING_WIFI, null, false);
         mLooper.dispatchAll();
         verify(mWifiManager, times(1)).startSoftAp(null);
         verifyNoMoreInteractions(mWifiManager);
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
 
         // Emulate externally-visible WifiManager effects, causing the
         // per-interface state machine to start up, and telling us that
@@ -931,15 +928,15 @@
         sendWifiApStateChanged(WIFI_AP_STATE_ENABLED, TEST_WLAN_IFNAME, IFACE_IP_MODE_TETHERED);
         mLooper.dispatchAll();
 
-        // We verify get/set called thrice here: twice for setup (on NMService) and once during
-        // teardown (on Netd) because all events happen over the course of the single
+        // We verify get/set called three times here: twice for setup and once during
+        // teardown because all events happen over the course of the single
         // dispatchAll() above. Note that once the IpServer IPv4 address config
         // code is refactored the two calls during shutdown will revert to one.
-        verify(mNMService, times(2)).getInterfaceConfig(TEST_WLAN_IFNAME);
-        verify(mNMService, times(2))
-                .setInterfaceConfig(eq(TEST_WLAN_IFNAME), any(InterfaceConfiguration.class));
-        verify(mNetd, times(1)).interfaceSetCfg(argThat(p -> TEST_WLAN_IFNAME.equals(p.ifName)));
-        verify(mNMService, times(1)).tetherInterface(TEST_WLAN_IFNAME);
+        verify(mNetd, times(3)).interfaceSetCfg(argThat(p -> TEST_WLAN_IFNAME.equals(p.ifName)));
+        verify(mNetd, times(1)).tetherInterfaceAdd(TEST_WLAN_IFNAME);
+        verify(mNetd, times(1)).networkAddInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+        verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(TEST_WLAN_IFNAME),
+                anyString(), anyString());
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
         verify(mWifiManager).updateInterfaceIpState(
@@ -949,18 +946,20 @@
         assertEquals(3, mTetheringDependencies.mIsTetheringSupportedCalls);
         verifyTetheringBroadcast(TEST_WLAN_IFNAME, EXTRA_AVAILABLE_TETHER);
         // This is called, but will throw.
-        verify(mNMService, times(1)).setIpForwardingEnabled(true);
+        verify(mNetd, times(1)).ipfwdEnableForwarding(TETHERING_NAME);
         // This never gets called because of the exception thrown above.
-        verify(mNMService, times(0)).startTethering(any(String[].class));
+        verify(mNetd, times(0)).tetherStartWithConfiguration(any());
         // When the master state machine transitions to an error state it tells
         // downstream interfaces, which causes us to tell Wi-Fi about the error
         // so it can take down AP mode.
-        verify(mNMService, times(1)).untetherInterface(TEST_WLAN_IFNAME);
+        verify(mNetd, times(1)).tetherApplyDnsInterfaces();
+        verify(mNetd, times(1)).tetherInterfaceRemove(TEST_WLAN_IFNAME);
+        verify(mNetd, times(1)).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_CONFIGURATION_ERROR);
 
         verifyNoMoreInteractions(mWifiManager);
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
     }
 
     private void runUserRestrictionsChange(
@@ -1232,9 +1231,9 @@
 
         verifyInterfaceServingModeStarted(TEST_P2P_IFNAME);
         verifyTetheringBroadcast(TEST_P2P_IFNAME, EXTRA_AVAILABLE_TETHER);
-        verify(mNMService, times(1)).setIpForwardingEnabled(true);
-        verify(mNMService, times(1)).startTethering(any(String[].class));
-        verifyNoMoreInteractions(mNMService);
+        verify(mNetd, times(1)).ipfwdEnableForwarding(TETHERING_NAME);
+        verify(mNetd, times(1)).tetherStartWithConfiguration(any());
+        verifyNoMoreInteractions(mNetd);
         verifyTetheringBroadcast(TEST_P2P_IFNAME, EXTRA_ACTIVE_LOCAL_ONLY);
         verify(mUpstreamNetworkMonitor, times(1)).startObserveAllNetworks();
         // This will be called twice, one is on entering IpServer.STATE_AVAILABLE,
@@ -1249,16 +1248,16 @@
         mTethering.interfaceRemoved(TEST_P2P_IFNAME);
         mLooper.dispatchAll();
 
-        verify(mNMService, times(1)).untetherInterface(TEST_P2P_IFNAME);
-        // {g,s}etInterfaceConfig() called twice for enabling and disabling IPv4.
-        verify(mNMService, times(2)).getInterfaceConfig(TEST_P2P_IFNAME);
-        verify(mNMService, times(2))
-                .setInterfaceConfig(eq(TEST_P2P_IFNAME), any(InterfaceConfiguration.class));
-        verify(mNMService, times(1)).stopTethering();
-        verify(mNMService, times(1)).setIpForwardingEnabled(false);
+        verify(mNetd, times(1)).tetherApplyDnsInterfaces();
+        verify(mNetd, times(1)).tetherInterfaceRemove(TEST_P2P_IFNAME);
+        verify(mNetd, times(1)).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_P2P_IFNAME);
+        // interfaceSetCfg() called once for enabling and twice for disabling IPv4.
+        verify(mNetd, times(3)).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
+        verify(mNetd, times(1)).tetherStop();
+        verify(mNetd, times(1)).ipfwdDisableForwarding(TETHERING_NAME);
         verify(mUpstreamNetworkMonitor, never()).getCurrentPreferredUpstream();
         verify(mUpstreamNetworkMonitor, never()).selectPreferredUpstreamType(any());
-        verifyNoMoreInteractions(mNMService);
+        verifyNoMoreInteractions(mNetd);
         // Asking for the last error after the per-interface state machine
         // has been reaped yields an unknown interface error.
         assertEquals(TETHER_ERROR_UNKNOWN_IFACE, mTethering.getLastTetherError(TEST_P2P_IFNAME));
@@ -1272,12 +1271,11 @@
         sendWifiP2pConnectionChanged(true, false, TEST_P2P_IFNAME);
         mLooper.dispatchAll();
 
-        verify(mNMService, never()).getInterfaceConfig(TEST_P2P_IFNAME);
-        verify(mNMService, never())
-                .setInterfaceConfig(eq(TEST_P2P_IFNAME), any(InterfaceConfiguration.class));
-        verify(mNMService, never()).tetherInterface(TEST_P2P_IFNAME);
-        verify(mNMService, never()).setIpForwardingEnabled(true);
-        verify(mNMService, never()).startTethering(any(String[].class));
+        verify(mNetd, never()).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
+        verify(mNetd, never()).tetherInterfaceAdd(TEST_P2P_IFNAME);
+        verify(mNetd, never()).networkAddInterface(INetd.LOCAL_NET_ID, TEST_P2P_IFNAME);
+        verify(mNetd, never()).ipfwdEnableForwarding(TETHERING_NAME);
+        verify(mNetd, never()).tetherStartWithConfiguration(any());
 
         // Emulate externally-visible WifiP2pManager effects, when wifi p2p group
         // is being removed.
@@ -1285,13 +1283,13 @@
         mTethering.interfaceRemoved(TEST_P2P_IFNAME);
         mLooper.dispatchAll();
 
-        verify(mNMService, never()).untetherInterface(TEST_P2P_IFNAME);
-        verify(mNMService, never()).getInterfaceConfig(TEST_P2P_IFNAME);
-        verify(mNMService, never())
-                .setInterfaceConfig(eq(TEST_P2P_IFNAME), any(InterfaceConfiguration.class));
-        verify(mNMService, never()).stopTethering();
-        verify(mNMService, never()).setIpForwardingEnabled(false);
-        verifyNoMoreInteractions(mNMService);
+        verify(mNetd, never()).tetherApplyDnsInterfaces();
+        verify(mNetd, never()).tetherInterfaceRemove(TEST_P2P_IFNAME);
+        verify(mNetd, never()).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_P2P_IFNAME);
+        verify(mNetd, never()).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
+        verify(mNetd, never()).tetherStop();
+        verify(mNetd, never()).ipfwdDisableForwarding(TETHERING_NAME);
+        verifyNoMoreInteractions(mNetd);
         // Asking for the last error after the per-interface state machine
         // has been reaped yields an unknown interface error.
         assertEquals(TETHER_ERROR_UNKNOWN_IFACE, mTethering.getLastTetherError(TEST_P2P_IFNAME));
@@ -1321,12 +1319,11 @@
         sendWifiP2pConnectionChanged(true, true, TEST_P2P_IFNAME);
         mLooper.dispatchAll();
 
-        verify(mNMService, never()).getInterfaceConfig(TEST_P2P_IFNAME);
-        verify(mNMService, never())
-                .setInterfaceConfig(eq(TEST_P2P_IFNAME), any(InterfaceConfiguration.class));
-        verify(mNMService, never()).tetherInterface(TEST_P2P_IFNAME);
-        verify(mNMService, never()).setIpForwardingEnabled(true);
-        verify(mNMService, never()).startTethering(any(String[].class));
+        verify(mNetd, never()).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
+        verify(mNetd, never()).tetherInterfaceAdd(TEST_P2P_IFNAME);
+        verify(mNetd, never()).networkAddInterface(INetd.LOCAL_NET_ID, TEST_P2P_IFNAME);
+        verify(mNetd, never()).ipfwdEnableForwarding(TETHERING_NAME);
+        verify(mNetd, never()).tetherStartWithConfiguration(any());
         assertEquals(TETHER_ERROR_UNKNOWN_IFACE, mTethering.getLastTetherError(TEST_P2P_IFNAME));
     }
     @Test
diff --git a/services/core/java/com/android/server/NetworkManagementService.java b/services/core/java/com/android/server/NetworkManagementService.java
index 0d496b6..1daed1b 100644
--- a/services/core/java/com/android/server/NetworkManagementService.java
+++ b/services/core/java/com/android/server/NetworkManagementService.java
@@ -58,10 +58,12 @@
 import android.net.NetworkStats;
 import android.net.NetworkUtils;
 import android.net.RouteInfo;
-import android.net.TetherConfigParcel;
 import android.net.TetherStatsParcel;
 import android.net.UidRange;
 import android.net.UidRangeParcel;
+import android.net.shared.NetdUtils;
+import android.net.shared.RouteUtils;
+import android.net.shared.RouteUtils.ModifyOperation;
 import android.net.util.NetdService;
 import android.os.BatteryStats;
 import android.os.Binder;
@@ -897,48 +899,14 @@
 
     @Override
     public void addRoute(int netId, RouteInfo route) {
-        modifyRoute(MODIFY_OPERATION_ADD, netId, route);
+        NetworkStack.checkNetworkStackPermission(mContext);
+        RouteUtils.modifyRoute(mNetdService, ModifyOperation.ADD, netId, route);
     }
 
     @Override
     public void removeRoute(int netId, RouteInfo route) {
-        modifyRoute(MODIFY_OPERATION_REMOVE, netId, route);
-    }
-
-    private void modifyRoute(boolean add, int netId, RouteInfo route) {
         NetworkStack.checkNetworkStackPermission(mContext);
-
-        final String ifName = route.getInterface();
-        final String dst = route.getDestination().toString();
-        final String nextHop;
-
-        switch (route.getType()) {
-            case RouteInfo.RTN_UNICAST:
-                if (route.hasGateway()) {
-                    nextHop = route.getGateway().getHostAddress();
-                } else {
-                    nextHop = INetd.NEXTHOP_NONE;
-                }
-                break;
-            case RouteInfo.RTN_UNREACHABLE:
-                nextHop = INetd.NEXTHOP_UNREACHABLE;
-                break;
-            case RouteInfo.RTN_THROW:
-                nextHop = INetd.NEXTHOP_THROW;
-                break;
-            default:
-                nextHop = INetd.NEXTHOP_NONE;
-                break;
-        }
-        try {
-            if (add) {
-                mNetdService.networkAddRoute(netId, ifName, dst, nextHop);
-            } else {
-                mNetdService.networkRemoveRoute(netId, ifName, dst, nextHop);
-            }
-        } catch (RemoteException | ServiceSpecificException e) {
-            throw new IllegalStateException(e);
-        }
+        RouteUtils.modifyRoute(mNetdService, ModifyOperation.REMOVE, netId, route);
     }
 
     private ArrayList<String> readRouteList(String filename) {
@@ -1022,12 +990,8 @@
     @Override
     public void startTetheringWithConfiguration(boolean usingLegacyDnsProxy, String[] dhcpRange) {
         NetworkStack.checkNetworkStackPermission(mContext);
-        // an odd number of addrs will fail
         try {
-            final TetherConfigParcel config = new TetherConfigParcel();
-            config.usingLegacyDnsProxy = usingLegacyDnsProxy;
-            config.dhcpRanges = dhcpRange;
-            mNetdService.tetherStartWithConfiguration(config);
+            NetdUtils.tetherStart(mNetdService, usingLegacyDnsProxy, dhcpRange);
         } catch (RemoteException | ServiceSpecificException e) {
             throw new IllegalStateException(e);
         }
@@ -1059,26 +1023,21 @@
     public void tetherInterface(String iface) {
         NetworkStack.checkNetworkStackPermission(mContext);
         try {
-            mNetdService.tetherInterfaceAdd(iface);
+            final LinkAddress addr = getInterfaceConfig(iface).getLinkAddress();
+            final IpPrefix dest = new IpPrefix(addr.getAddress(), addr.getPrefixLength());
+            NetdUtils.tetherInterface(mNetdService, iface, dest);
         } catch (RemoteException | ServiceSpecificException e) {
             throw new IllegalStateException(e);
         }
-        List<RouteInfo> routes = new ArrayList<>();
-        // The RouteInfo constructor truncates the LinkAddress to a network prefix, thus making it
-        // suitable to use as a route destination.
-        routes.add(new RouteInfo(getInterfaceConfig(iface).getLinkAddress(), null, iface));
-        addInterfaceToLocalNetwork(iface, routes);
     }
 
     @Override
     public void untetherInterface(String iface) {
         NetworkStack.checkNetworkStackPermission(mContext);
         try {
-            mNetdService.tetherInterfaceRemove(iface);
+            NetdUtils.untetherInterface(mNetdService, iface);
         } catch (RemoteException | ServiceSpecificException e) {
             throw new IllegalStateException(e);
-        } finally {
-            removeInterfaceFromLocalNetwork(iface);
         }
     }
 
@@ -2121,16 +2080,8 @@
     @Override
     public void addInterfaceToLocalNetwork(String iface, List<RouteInfo> routes) {
         modifyInterfaceInNetwork(MODIFY_OPERATION_ADD, INetd.LOCAL_NET_ID, iface);
-
-        for (RouteInfo route : routes) {
-            if (!route.isDefaultRoute()) {
-                modifyRoute(MODIFY_OPERATION_ADD, INetd.LOCAL_NET_ID, route);
-            }
-        }
-
-        // IPv6 link local should be activated always.
-        modifyRoute(MODIFY_OPERATION_ADD, INetd.LOCAL_NET_ID,
-                new RouteInfo(new IpPrefix("fe80::/64"), null, iface));
+        // modifyInterfaceInNetwork already check calling permission.
+        RouteUtils.addRoutesToLocalNetwork(mNetdService, iface, routes);
     }
 
     @Override
@@ -2140,17 +2091,8 @@
 
     @Override
     public int removeRoutesFromLocalNetwork(List<RouteInfo> routes) {
-        int failures = 0;
-
-        for (RouteInfo route : routes) {
-            try {
-                modifyRoute(MODIFY_OPERATION_REMOVE, INetd.LOCAL_NET_ID, route);
-            } catch (IllegalStateException e) {
-                failures++;
-            }
-        }
-
-        return failures;
+        NetworkStack.checkNetworkStackPermission(mContext);
+        return RouteUtils.removeRoutesFromLocalNetwork(mNetdService, routes);
     }
 
     @Override