diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractAppIdleTestCase.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractAppIdleTestCase.java
index bb492a1..f9e30b6 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractAppIdleTestCase.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractAppIdleTestCase.java
@@ -78,6 +78,17 @@
         stopForegroundService();
         assertAppIdle(true);
         assertBackgroundNetworkAccess(false);
+
+        // Set Idle after foreground service start.
+        launchComponentAndAssertNetworkAccess(TYPE_COMPONENT_FOREGROUND_SERVICE);
+        setAppIdle(true);
+        addPowerSaveModeWhitelist(TEST_PKG);
+        removePowerSaveModeWhitelist(TEST_PKG);
+        assertForegroundServiceNetworkAccess();
+        stopForegroundService();
+        assertAppIdle(true);
+        assertBackgroundNetworkAccess(false);
+
     }
 
     @Test
diff --git a/tests/cts/net/jni/NativeMultinetworkJni.cpp b/tests/cts/net/jni/NativeMultinetworkJni.cpp
index cd94709..60e31bc 100644
--- a/tests/cts/net/jni/NativeMultinetworkJni.cpp
+++ b/tests/cts/net/jni/NativeMultinetworkJni.cpp
@@ -458,20 +458,16 @@
     setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo));
 
     // For reference see:
-    //     https://tools.ietf.org/html/draft-tsvwg-quic-protocol#section-6.1
+    //     https://datatracker.ietf.org/doc/html/draft-ietf-quic-invariants
     uint8_t quic_packet[1200] = {
-        0x0d,                    // public flags:
-                                 //   - version present (0x01),
-                                 //   - 64bit connection ID (0x0c),
-                                 //   - 1 byte packet number (0x00)
+        0xc0,                    // long header
+        0xaa, 0xda, 0xca, 0xca,  // reserved-space version number
+        0x08,                    // destination connection ID length
         0, 0, 0, 0, 0, 0, 0, 0,  // 64bit connection ID
-        0xaa, 0xda, 0xca, 0xaa,  // reserved-space version number
-        1,                       // 1 byte packet number
-        0x00,                    // private flags
-        0x07,                    // PING frame (cuz why not)
+        0x00,                    // source connection ID length
     };
 
-    arc4random_buf(quic_packet + 1, 8);  // random connection ID
+    arc4random_buf(quic_packet + 6, 8);  // random connection ID
 
     uint8_t response[1500];
     ssize_t sent, rcvd;
@@ -496,7 +492,7 @@
                   i + 1, MAX_RETRIES, rcvd, errnum);
         }
     }
-    if (rcvd < 9) {
+    if (rcvd < 15) {
         LOGD("QUIC UDP %s: sent=%zd but rcvd=%zd, errno=%d", kPort, sent, rcvd, errnum);
         if (rcvd <= 0) {
             LOGD("Does this network block UDP port %s?", kPort);
@@ -505,7 +501,7 @@
         return -EPROTO;
     }
 
-    int conn_id_cmp = memcmp(quic_packet + 1, response + 1, 8);
+    int conn_id_cmp = memcmp(quic_packet + 6, response + 7, 8);
     if (conn_id_cmp != 0) {
         LOGD("sent and received connection IDs do not match");
         close(fd);
diff --git a/tests/cts/net/src/android/net/cts/CaptivePortalTest.kt b/tests/cts/net/src/android/net/cts/CaptivePortalTest.kt
index f24053c..eb5048f 100644
--- a/tests/cts/net/src/android/net/cts/CaptivePortalTest.kt
+++ b/tests/cts/net/src/android/net/cts/CaptivePortalTest.kt
@@ -30,11 +30,9 @@
 import android.net.NetworkRequest
 import android.net.Uri
 import android.net.cts.NetworkValidationTestUtil.clearValidationTestUrlsDeviceConfig
-import android.net.cts.NetworkValidationTestUtil.runAsShell
 import android.net.cts.NetworkValidationTestUtil.setHttpUrlDeviceConfig
 import android.net.cts.NetworkValidationTestUtil.setHttpsUrlDeviceConfig
 import android.net.cts.NetworkValidationTestUtil.setUrlExpirationDeviceConfig
-import com.android.testutils.TestHttpServer.Request
 import android.net.cts.util.CtsNetUtils
 import android.net.util.NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTPS_URL
 import android.net.util.NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTP_URL
@@ -47,7 +45,9 @@
 import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
 import androidx.test.runner.AndroidJUnit4
 import com.android.testutils.TestHttpServer
+import com.android.testutils.TestHttpServer.Request
 import com.android.testutils.isDevSdkInRange
+import com.android.testutils.runAsShell
 import fi.iki.elonen.NanoHTTPD.Response.Status
 import junit.framework.AssertionFailedError
 import org.junit.After
diff --git a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
index 4f42ccc..db4e3e7 100644
--- a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
+++ b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
@@ -224,6 +224,16 @@
         if (mCtsNetUtils.cellConnectAttempted()) {
             mCtsNetUtils.disconnectFromCell();
         }
+
+        // All tests in this class require a working Internet connection as they start. Make
+        // sure there is still one as they end that's ready to use for the next test to use.
+        final TestNetworkCallback callback = new TestNetworkCallback();
+        mCm.registerDefaultNetworkCallback(callback);
+        try {
+            assertNotNull("Couldn't restore Internet connectivity", callback.waitForAvailable());
+        } finally {
+            mCm.unregisterNetworkCallback(callback);
+        }
     }
 
     /**
diff --git a/tests/cts/net/src/android/net/cts/NetworkValidationTest.kt b/tests/cts/net/src/android/net/cts/NetworkValidationTest.kt
index ec656de..5290f0d 100644
--- a/tests/cts/net/src/android/net/cts/NetworkValidationTest.kt
+++ b/tests/cts/net/src/android/net/cts/NetworkValidationTest.kt
@@ -31,7 +31,6 @@
 import android.net.TestNetworkInterface
 import android.net.TestNetworkManager
 import android.net.Uri
-import android.net.cts.NetworkValidationTestUtil.runAsShell
 import android.net.dhcp.DhcpDiscoverPacket
 import android.net.dhcp.DhcpPacket
 import android.net.dhcp.DhcpPacket.DHCP_MESSAGE_TYPE
@@ -45,8 +44,7 @@
 import androidx.test.runner.AndroidJUnit4
 import com.android.net.module.util.Inet4AddressUtils.getBroadcastAddress
 import com.android.net.module.util.Inet4AddressUtils.getPrefixMaskAsInet4Address
-import com.android.server.util.NetworkStackConstants.IPV4_ADDR_ANY
-import com.android.testutils.ArpResponder
+import com.android.net.module.util.NetworkStackConstants.IPV4_ADDR_ANY
 import com.android.testutils.DevSdkIgnoreRule
 import com.android.testutils.DhcpClientPacketFilter
 import com.android.testutils.DhcpOptionFilter
@@ -54,10 +52,10 @@
 import com.android.testutils.TapPacketReader
 import com.android.testutils.TestHttpServer
 import com.android.testutils.TestableNetworkCallback
+import com.android.testutils.runAsShell
 import fi.iki.elonen.NanoHTTPD.Response.Status
 import org.junit.After
 import org.junit.Assume.assumeFalse
-import org.junit.Assume.assumeTrue
 import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
@@ -131,7 +129,7 @@
                 handlerThread.threadHandler,
                 iface.fileDescriptor.fileDescriptor,
                 MAX_PACKET_LENGTH)
-        handlerThread.threadHandler.post { reader.start() }
+        reader.startAsyncForTest()
         httpServer.start()
 
         // Pad the listening port to make sure it is always of length 5. This ensures the URL has
@@ -233,7 +231,7 @@
     timeoutMs: Long,
     type: Byte
 ): T {
-    val packetBytes = popPacket(timeoutMs, DhcpClientPacketFilter()
+    val packetBytes = poll(timeoutMs, DhcpClientPacketFilter()
             .and(DhcpOptionFilter(DHCP_MESSAGE_TYPE, type)))
             ?: fail("${packetType.simpleName} not received within timeout")
     val packet = DhcpPacket.decodeFullPacket(packetBytes, packetBytes.size, DhcpPacket.ENCAP_L2)
diff --git a/tests/cts/net/src/android/net/cts/NetworkValidationTestUtil.kt b/tests/cts/net/src/android/net/cts/NetworkValidationTestUtil.kt
index 5ef1854..f6fc75b 100644
--- a/tests/cts/net/src/android/net/cts/NetworkValidationTestUtil.kt
+++ b/tests/cts/net/src/android/net/cts/NetworkValidationTestUtil.kt
@@ -19,9 +19,7 @@
 import android.Manifest
 import android.net.util.NetworkStackUtils
 import android.provider.DeviceConfig
-import com.android.compatibility.common.util.SystemUtil.runWithShellPermissionIdentity
-import com.android.compatibility.common.util.ThrowingRunnable
-import kotlin.test.fail
+import com.android.testutils.runAsShell
 
 /**
  * Collection of utility methods for configuring network validation.
@@ -67,13 +65,4 @@
                     DeviceConfig.NAMESPACE_CONNECTIVITY, configKey, value, false /* makeDefault */)
         }
     }
-
-    /**
-     * Wrapper around runWithShellPermissionIdentity with kotlin-like syntax.
-     */
-    fun <T> runAsShell(vararg permissions: String, task: () -> T): T {
-        var ret: T? = null
-        runWithShellPermissionIdentity(ThrowingRunnable { ret = task() }, *permissions)
-        return ret ?: fail("ThrowingRunnable did not return")
-    }
 }
\ No newline at end of file