diff --git a/tests/cts/net/TEST_MAPPING b/TEST_MAPPING
similarity index 88%
rename from tests/cts/net/TEST_MAPPING
rename to TEST_MAPPING
index 8f65b65..1db4baa 100644
--- a/tests/cts/net/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -1,5 +1,6 @@
 {
-  // TODO: move to mainline-presubmit once supported
+  // Run in addition to mainline-presubmit as mainline-presubmit is not
+  // supported in every branch.
   "presubmit": [
     {
       "name": "CtsNetTestCasesLatestSdk",
diff --git a/Tethering/Android.bp b/Tethering/Android.bp
index 23aa7f8..d8557ad 100644
--- a/Tethering/Android.bp
+++ b/Tethering/Android.bp
@@ -67,6 +67,9 @@
         "liblog",
         "libnativehelper_compat_libc++",
     ],
+    static_libs: [
+        "libnetjniutils",
+    ],
 
     // We cannot use plain "libc++" here to link libc++ dynamically because it results in:
     //   java.lang.UnsatisfiedLinkError: dlopen failed: library "libc++_shared.so" not found
diff --git a/Tethering/jni/android_net_util_TetheringUtils.cpp b/Tethering/jni/android_net_util_TetheringUtils.cpp
index 94c871d..7bfb6da 100644
--- a/Tethering/jni/android_net_util_TetheringUtils.cpp
+++ b/Tethering/jni/android_net_util_TetheringUtils.cpp
@@ -19,8 +19,8 @@
 #include <jni.h>
 #include <linux/filter.h>
 #include <nativehelper/JNIHelp.h>
-#include <nativehelper/JNIHelpCompat.h>
 #include <nativehelper/ScopedUtfChars.h>
+#include <netjniutils/netjniutils.h>
 #include <net/if.h>
 #include <netinet/ether.h>
 #include <netinet/ip6.h>
@@ -57,7 +57,7 @@
         filter_code,
     };
 
-    int fd = jniGetFDFromFileDescriptor(env, javaFd);
+    int fd = netjniutils::GetNativeFileDescriptor(env, javaFd);
     if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) != 0) {
         jniThrowExceptionFmt(env, "java/net/SocketException",
                 "setsockopt(SO_ATTACH_FILTER): %s", strerror(errno));
@@ -79,7 +79,7 @@
 {
     static const int kLinkLocalHopLimit = 255;
 
-    int fd = jniGetFDFromFileDescriptor(env, javaFd);
+    int fd = netjniutils::GetNativeFileDescriptor(env, javaFd);
 
     // Set an ICMPv6 filter that only passes Router Solicitations.
     struct icmp6_filter rs_only;
diff --git a/Tethering/src/android/net/ip/NeighborPacketForwarder.java b/Tethering/src/android/net/ip/NeighborPacketForwarder.java
index 73fc833..084743d 100644
--- a/Tethering/src/android/net/ip/NeighborPacketForwarder.java
+++ b/Tethering/src/android/net/ip/NeighborPacketForwarder.java
@@ -25,7 +25,6 @@
 import static android.system.OsConstants.SOCK_RAW;
 
 import android.net.util.InterfaceParams;
-import android.net.util.PacketReader;
 import android.net.util.SocketUtils;
 import android.net.util.TetheringUtils;
 import android.os.Handler;
@@ -33,6 +32,8 @@
 import android.system.Os;
 import android.util.Log;
 
+import com.android.net.module.util.PacketReader;
+
 import java.io.FileDescriptor;
 import java.io.IOException;
 import java.net.Inet6Address;
diff --git a/tests/cts/tethering/OWNERS b/tests/cts/OWNERS
similarity index 81%
rename from tests/cts/tethering/OWNERS
rename to tests/cts/OWNERS
index cd6abeb..4264345 100644
--- a/tests/cts/tethering/OWNERS
+++ b/tests/cts/OWNERS
@@ -1,4 +1,4 @@
 # Bug component: 31808
+set noparent
 lorenzo@google.com
-satk@google.com
-
+satk@google.com
\ No newline at end of file
diff --git a/tests/cts/hostside/OWNERS b/tests/cts/hostside/OWNERS
index 52c8053..20bc55e 100644
--- a/tests/cts/hostside/OWNERS
+++ b/tests/cts/hostside/OWNERS
@@ -1,4 +1,4 @@
 # Bug component: 61373
+# Inherits parent owners
 sudheersai@google.com
-lorenzo@google.com
 jchalard@google.com
diff --git a/tests/cts/net/OWNERS b/tests/cts/net/OWNERS
index 7722bb3..432bd9b 100644
--- a/tests/cts/net/OWNERS
+++ b/tests/cts/net/OWNERS
@@ -1,5 +1,3 @@
 # Bug component: 31808
-lorenzo@google.com
-satk@google.com
-
+# Inherits parent owners
 per-file src/android/net/cts/NetworkWatchlistTest.java=alanstokes@google.com
diff --git a/tests/cts/net/src/android/net/cts/NetworkAgentTest.kt b/tests/cts/net/src/android/net/cts/NetworkAgentTest.kt
index 85d0a2e..87aa2a3 100644
--- a/tests/cts/net/src/android/net/cts/NetworkAgentTest.kt
+++ b/tests/cts/net/src/android/net/cts/NetworkAgentTest.kt
@@ -18,6 +18,8 @@
 import android.app.Instrumentation
 import android.content.Context
 import android.net.ConnectivityManager
+import android.net.InetAddresses
+import android.net.IpPrefix
 import android.net.KeepalivePacketData
 import android.net.LinkAddress
 import android.net.LinkProperties
@@ -34,9 +36,20 @@
 import android.net.NetworkAgent.VALID_NETWORK
 import android.net.NetworkAgentConfig
 import android.net.NetworkCapabilities
+import android.net.NetworkCapabilities.NET_CAPABILITY_INTERNET
+import android.net.NetworkCapabilities.NET_CAPABILITY_NOT_CONGESTED
+import android.net.NetworkCapabilities.NET_CAPABILITY_NOT_METERED
+import android.net.NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING
+import android.net.NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED
+import android.net.NetworkCapabilities.NET_CAPABILITY_NOT_VPN
+import android.net.NetworkCapabilities.NET_CAPABILITY_TEMPORARILY_NOT_METERED
+import android.net.NetworkCapabilities.NET_CAPABILITY_TRUSTED
+import android.net.NetworkCapabilities.TRANSPORT_TEST
+import android.net.NetworkCapabilities.TRANSPORT_VPN
 import android.net.NetworkInfo
 import android.net.NetworkProvider
 import android.net.NetworkRequest
+import android.net.RouteInfo
 import android.net.SocketKeepalive
 import android.net.StringNetworkSpecifier
 import android.net.Uri
@@ -57,6 +70,7 @@
 import android.os.Looper
 import android.os.Message
 import android.os.Messenger
+import android.util.DebugUtils.valueToString
 import androidx.test.InstrumentationRegistry
 import androidx.test.runner.AndroidJUnit4
 import com.android.internal.util.AsyncChannel
@@ -80,7 +94,6 @@
 import org.mockito.Mockito.doReturn
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.verify
-import java.net.InetAddress
 import java.time.Duration
 import java.util.Arrays
 import java.util.UUID
@@ -122,8 +135,8 @@
     @Rule @JvmField
     val ignoreRule = DevSdkIgnoreRule(ignoreClassUpTo = Build.VERSION_CODES.Q)
 
-    private val LOCAL_IPV4_ADDRESS = InetAddress.parseNumericAddress("192.0.2.1")
-    private val REMOTE_IPV4_ADDRESS = InetAddress.parseNumericAddress("192.0.2.2")
+    private val LOCAL_IPV4_ADDRESS = InetAddresses.parseNumericAddress("192.0.2.1")
+    private val REMOTE_IPV4_ADDRESS = InetAddresses.parseNumericAddress("192.0.2.2")
 
     private val mCM = realContext.getSystemService(ConnectivityManager::class.java)
     private val mHandlerThread = HandlerThread("${javaClass.simpleName} handler thread")
@@ -314,22 +327,23 @@
     private fun createNetworkAgent(
         context: Context = realContext,
         name: String? = null,
-        nc: NetworkCapabilities = NetworkCapabilities(),
-        lp: LinkProperties = LinkProperties()
+        initialNc: NetworkCapabilities? = null,
+        initialLp: LinkProperties? = null
     ): TestableNetworkAgent {
-        nc.apply {
-            addTransportType(NetworkCapabilities.TRANSPORT_TEST)
-            removeCapability(NetworkCapabilities.NET_CAPABILITY_TRUSTED)
-            removeCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
-            addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED)
-            addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING)
-            addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)
+        val nc = initialNc ?: NetworkCapabilities().apply {
+            addTransportType(TRANSPORT_TEST)
+            removeCapability(NET_CAPABILITY_TRUSTED)
+            removeCapability(NET_CAPABILITY_INTERNET)
+            addCapability(NET_CAPABILITY_NOT_SUSPENDED)
+            addCapability(NET_CAPABILITY_NOT_ROAMING)
+            addCapability(NET_CAPABILITY_NOT_VPN)
             if (null != name) {
                 setNetworkSpecifier(StringNetworkSpecifier(name))
             }
         }
-        lp.apply {
-            addLinkAddress(LinkAddress(LOCAL_IPV4_ADDRESS, 0))
+        val lp = initialLp ?: LinkProperties().apply {
+            addLinkAddress(LinkAddress(LOCAL_IPV4_ADDRESS, 32))
+            addRoute(RouteInfo(IpPrefix("0.0.0.0/0"), null, null))
         }
         val config = NetworkAgentConfig.Builder().build()
         return TestableNetworkAgent(context, mHandlerThread.looper, nc, lp, config).also {
@@ -341,7 +355,7 @@
             Pair<TestableNetworkAgent, TestableNetworkCallback> {
         val request: NetworkRequest = NetworkRequest.Builder()
                 .clearCapabilities()
-                .addTransportType(NetworkCapabilities.TRANSPORT_TEST)
+                .addTransportType(TRANSPORT_TEST)
                 .build()
         val callback = TestableNetworkCallback(timeoutMs = DEFAULT_TIMEOUT_MS)
         requestNetwork(request, callback)
@@ -386,7 +400,7 @@
         val callbacks = thresholds.map { strength ->
             val request = NetworkRequest.Builder()
                     .clearCapabilities()
-                    .addTransportType(NetworkCapabilities.TRANSPORT_TEST)
+                    .addTransportType(TRANSPORT_TEST)
                     .setSignalStrength(strength)
                     .build()
             TestableNetworkCallback(DEFAULT_TIMEOUT_MS).also {
@@ -486,10 +500,10 @@
             it.getInterfaceName() == ifaceName
         }
         val nc = NetworkCapabilities(agent.nc)
-        nc.addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
+        nc.addCapability(NET_CAPABILITY_NOT_METERED)
         agent.sendNetworkCapabilities(nc)
         callback.expectCapabilitiesThat(agent.network) {
-            it.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
+            it.hasCapability(NET_CAPABILITY_NOT_METERED)
         }
     }
 
@@ -503,12 +517,12 @@
         val name2 = UUID.randomUUID().toString()
         val request1 = NetworkRequest.Builder()
                 .clearCapabilities()
-                .addTransportType(NetworkCapabilities.TRANSPORT_TEST)
+                .addTransportType(TRANSPORT_TEST)
                 .setNetworkSpecifier(StringNetworkSpecifier(name1))
                 .build()
         val request2 = NetworkRequest.Builder()
                 .clearCapabilities()
-                .addTransportType(NetworkCapabilities.TRANSPORT_TEST)
+                .addTransportType(TRANSPORT_TEST)
                 .setNetworkSpecifier(StringNetworkSpecifier(name2))
                 .build()
         val callback1 = TestableNetworkCallback(timeoutMs = DEFAULT_TIMEOUT_MS)
@@ -519,7 +533,7 @@
         // Then file the interesting request
         val request = NetworkRequest.Builder()
                 .clearCapabilities()
-                .addTransportType(NetworkCapabilities.TRANSPORT_TEST)
+                .addTransportType(TRANSPORT_TEST)
                 .build()
         val callback = TestableNetworkCallback(timeoutMs = DEFAULT_TIMEOUT_MS)
         requestNetwork(request, callback)
@@ -551,52 +565,71 @@
     @IgnoreUpTo(Build.VERSION_CODES.R)
     fun testSetUnderlyingNetworks() {
         val request = NetworkRequest.Builder()
-                .addTransportType(NetworkCapabilities.TRANSPORT_TEST)
-                .addTransportType(NetworkCapabilities.TRANSPORT_VPN)
-                .removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)
-                .removeCapability(NetworkCapabilities.NET_CAPABILITY_TRUSTED) // TODO: add to VPN!
+                .addTransportType(TRANSPORT_TEST)
+                .addTransportType(TRANSPORT_VPN)
+                .removeCapability(NET_CAPABILITY_NOT_VPN)
+                .removeCapability(NET_CAPABILITY_TRUSTED) // TODO: add to VPN!
                 .build()
-        val callback = TestableNetworkCallback()
-        mCM.registerNetworkCallback(request, callback)
+        val callback = TestableNetworkCallback(timeoutMs = DEFAULT_TIMEOUT_MS)
+        registerNetworkCallback(request, callback)
 
         val nc = NetworkCapabilities().apply {
-            addTransportType(NetworkCapabilities.TRANSPORT_TEST)
-            addTransportType(NetworkCapabilities.TRANSPORT_VPN)
-            removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)
+            addTransportType(TRANSPORT_TEST)
+            addTransportType(TRANSPORT_VPN)
+            removeCapability(NET_CAPABILITY_NOT_VPN)
         }
         val defaultNetwork = mCM.activeNetwork
         assertNotNull(defaultNetwork)
-        val defaultNetworkTransports = mCM.getNetworkCapabilities(defaultNetwork).transportTypes
+        val defaultNetworkCapabilities = mCM.getNetworkCapabilities(defaultNetwork)
+        val defaultNetworkTransports = defaultNetworkCapabilities.transportTypes
 
-        val agent = createNetworkAgent(nc = nc)
+        val agent = createNetworkAgent(initialNc = nc)
         agent.register()
         agent.markConnected()
         callback.expectAvailableThenValidatedCallbacks(agent.network!!)
 
+        // Check that the default network's transport is propagated to the VPN.
         var vpnNc = mCM.getNetworkCapabilities(agent.network)
         assertNotNull(vpnNc)
-        assertTrue(NetworkCapabilities.TRANSPORT_VPN in vpnNc.transportTypes)
+
+        val testAndVpn = intArrayOf(TRANSPORT_TEST, TRANSPORT_VPN)
+        assertTrue(hasAllTransports(vpnNc, testAndVpn))
+        assertFalse(vpnNc.hasCapability(NET_CAPABILITY_NOT_VPN))
         assertTrue(hasAllTransports(vpnNc, defaultNetworkTransports),
                 "VPN transports ${Arrays.toString(vpnNc.transportTypes)}" +
                 " lacking transports from ${Arrays.toString(defaultNetworkTransports)}")
 
+        // Check that when no underlying networks are announced the underlying transport disappears.
         agent.setUnderlyingNetworks(listOf<Network>())
         callback.expectCapabilitiesThat(agent.network!!) {
-            it.transportTypes.size == 1 && it.hasTransport(NetworkCapabilities.TRANSPORT_VPN)
+            it.transportTypes.size == 2 && hasAllTransports(it, testAndVpn)
         }
 
-        val expectedTransports = (defaultNetworkTransports.toSet() +
-                NetworkCapabilities.TRANSPORT_VPN).toIntArray()
+        // Put the underlying network back and check that the underlying transport reappears.
+        val expectedTransports = (defaultNetworkTransports.toSet() + TRANSPORT_TEST + TRANSPORT_VPN)
+                .toIntArray()
         agent.setUnderlyingNetworks(null)
         callback.expectCapabilitiesThat(agent.network!!) {
             it.transportTypes.size == expectedTransports.size &&
                     hasAllTransports(it, expectedTransports)
         }
 
+        // Check that some underlying capabilities are propagated.
+        // This is not very accurate because the test does not control the capabilities of the
+        // underlying networks, and because not congested, not roaming, and not suspended are the
+        // default anyway. It's still useful as an extra check though.
+        vpnNc = mCM.getNetworkCapabilities(agent.network)
+        for (cap in listOf(NET_CAPABILITY_NOT_CONGESTED,
+                NET_CAPABILITY_NOT_ROAMING,
+                NET_CAPABILITY_NOT_SUSPENDED)) {
+            val capStr = valueToString(NetworkCapabilities::class.java, "NET_CAPABILITY_", cap)
+            if (defaultNetworkCapabilities.hasCapability(cap) && !vpnNc.hasCapability(cap)) {
+                fail("$capStr not propagated from underlying: $defaultNetworkCapabilities")
+            }
+        }
+
         agent.unregister()
         callback.expectCallback<Lost>(agent.network)
-
-        mCM.unregisterNetworkCallback(callback)
     }
 
     @Test
@@ -687,7 +720,7 @@
         // First create a request to make sure the network is kept up
         val request1 = NetworkRequest.Builder()
                 .clearCapabilities()
-                .addTransportType(NetworkCapabilities.TRANSPORT_TEST)
+                .addTransportType(TRANSPORT_TEST)
                 .build()
         val callback1 = TestableNetworkCallback(timeoutMs = DEFAULT_TIMEOUT_MS).also {
             registerNetworkCallback(request1, it)
@@ -697,7 +730,7 @@
         // Then file the interesting request
         val request = NetworkRequest.Builder()
                 .clearCapabilities()
-                .addTransportType(NetworkCapabilities.TRANSPORT_TEST)
+                .addTransportType(TRANSPORT_TEST)
                 .build()
         val callback = TestableNetworkCallback(timeoutMs = DEFAULT_TIMEOUT_MS)
         requestNetwork(request, callback)
@@ -708,18 +741,18 @@
 
             // Send TEMP_NOT_METERED and check that the callback is called appropriately.
             val nc1 = NetworkCapabilities(agent.nc)
-                    .addCapability(NetworkCapabilities.NET_CAPABILITY_TEMPORARILY_NOT_METERED)
+                    .addCapability(NET_CAPABILITY_TEMPORARILY_NOT_METERED)
             agent.sendNetworkCapabilities(nc1)
             callback.expectCapabilitiesThat(agent.network) {
-                it.hasCapability(NetworkCapabilities.NET_CAPABILITY_TEMPORARILY_NOT_METERED)
+                it.hasCapability(NET_CAPABILITY_TEMPORARILY_NOT_METERED)
             }
 
             // Remove TEMP_NOT_METERED and check that the callback is called appropriately.
             val nc2 = NetworkCapabilities(agent.nc)
-                    .removeCapability(NetworkCapabilities.NET_CAPABILITY_TEMPORARILY_NOT_METERED)
+                    .removeCapability(NET_CAPABILITY_TEMPORARILY_NOT_METERED)
             agent.sendNetworkCapabilities(nc2)
             callback.expectCapabilitiesThat(agent.network) {
-                !it.hasCapability(NetworkCapabilities.NET_CAPABILITY_TEMPORARILY_NOT_METERED)
+                !it.hasCapability(NET_CAPABILITY_TEMPORARILY_NOT_METERED)
             }
         }