diff --git a/tests/cts/net/src/android/net/cts/MultinetworkApiTest.java b/tests/cts/net/src/android/net/cts/MultinetworkApiTest.java
index 691ab99..17a9ca2 100644
--- a/tests/cts/net/src/android/net/cts/MultinetworkApiTest.java
+++ b/tests/cts/net/src/android/net/cts/MultinetworkApiTest.java
@@ -18,21 +18,18 @@
 
 import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
 
-import android.content.Context;
 import android.content.ContentResolver;
+import android.content.Context;
 import android.net.ConnectivityManager;
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.NetworkUtils;
 import android.net.cts.util.CtsNetUtils;
 import android.platform.test.annotations.AppModeFull;
-import android.provider.Settings;
 import android.system.ErrnoException;
 import android.system.OsConstants;
 import android.test.AndroidTestCase;
 
-import java.util.ArrayList;
-
 public class MultinetworkApiTest extends AndroidTestCase {
 
     static {
@@ -75,26 +72,8 @@
         super.tearDown();
     }
 
-    private Network[] getTestableNetworks() {
-        final ArrayList<Network> testableNetworks = new ArrayList<Network>();
-        for (Network network : mCM.getAllNetworks()) {
-            final NetworkCapabilities nc = mCM.getNetworkCapabilities(network);
-            if (nc != null
-                    && nc.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)
-                    && nc.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)) {
-                testableNetworks.add(network);
-            }
-        }
-
-        assertTrue(
-                "This test requires that at least one network be connected. " +
-                "Please ensure that the device is connected to a network.",
-                testableNetworks.size() >= 1);
-        return testableNetworks.toArray(new Network[0]);
-    }
-
     public void testGetaddrinfo() throws ErrnoException {
-        for (Network network : getTestableNetworks()) {
+        for (Network network : mCtsNetUtils.getTestableNetworks()) {
             int errno = runGetaddrinfoCheck(network.getNetworkHandle());
             if (errno != 0) {
                 throw new ErrnoException(
@@ -109,7 +88,7 @@
         assertNull(mCM.getProcessDefaultNetwork());
         assertEquals(0, NetworkUtils.getBoundNetworkForProcess());
 
-        for (Network network : getTestableNetworks()) {
+        for (Network network : mCtsNetUtils.getTestableNetworks()) {
             mCM.setProcessDefaultNetwork(null);
             assertNull(mCM.getProcessDefaultNetwork());
 
@@ -128,7 +107,7 @@
             mCM.setProcessDefaultNetwork(null);
         }
 
-        for (Network network : getTestableNetworks()) {
+        for (Network network : mCtsNetUtils.getTestableNetworks()) {
             NetworkUtils.bindProcessToNetwork(0);
             assertNull(mCM.getBoundNetworkForProcess());
 
@@ -148,7 +127,7 @@
 
     @AppModeFull(reason = "CHANGE_NETWORK_STATE permission can't be granted to instant apps")
     public void testSetsocknetwork() throws ErrnoException {
-        for (Network network : getTestableNetworks()) {
+        for (Network network : mCtsNetUtils.getTestableNetworks()) {
             int errno = runSetsocknetwork(network.getNetworkHandle());
             if (errno != 0) {
                 throw new ErrnoException(
@@ -158,7 +137,7 @@
     }
 
     public void testNativeDatagramTransmission() throws ErrnoException {
-        for (Network network : getTestableNetworks()) {
+        for (Network network : mCtsNetUtils.getTestableNetworks()) {
             int errno = runDatagramCheck(network.getNetworkHandle());
             if (errno != 0) {
                 throw new ErrnoException(
@@ -181,7 +160,7 @@
 
     public void testNetworkHandle() {
         // Test Network -> NetworkHandle -> Network results in the same Network.
-        for (Network network : getTestableNetworks()) {
+        for (Network network : mCtsNetUtils.getTestableNetworks()) {
             long networkHandle = network.getNetworkHandle();
             Network newNetwork = Network.fromNetworkHandle(networkHandle);
             assertEquals(newNetwork, network);
@@ -203,7 +182,7 @@
     }
 
     public void testResNApi() throws Exception {
-        final Network[] testNetworks = getTestableNetworks();
+        final Network[] testNetworks = mCtsNetUtils.getTestableNetworks();
 
         for (Network network : testNetworks) {
             // Throws AssertionError directly in jni function if test fail.
@@ -229,7 +208,7 @@
         // b/144521720
         try {
             mCtsNetUtils.setPrivateDnsStrictMode(GOOGLE_PRIVATE_DNS_SERVER);
-            for (Network network : getTestableNetworks()) {
+            for (Network network : mCtsNetUtils.getTestableNetworks()) {
               // Wait for private DNS setting to propagate.
               mCtsNetUtils.awaitPrivateDnsSetting("NxDomain test wait private DNS setting timeout",
                         network, GOOGLE_PRIVATE_DNS_SERVER, true);
diff --git a/tests/cts/net/util/java/android/net/cts/util/CtsNetUtils.java b/tests/cts/net/util/java/android/net/cts/util/CtsNetUtils.java
index d817630..0c4f794 100644
--- a/tests/cts/net/util/java/android/net/cts/util/CtsNetUtils.java
+++ b/tests/cts/net/util/java/android/net/cts/util/CtsNetUtils.java
@@ -57,6 +57,8 @@
 import android.text.TextUtils;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import com.android.compatibility.common.util.PollingCheck;
 import com.android.compatibility.common.util.ShellIdentityUtils;
 import com.android.compatibility.common.util.SystemUtil;
@@ -68,6 +70,8 @@
 import java.io.OutputStream;
 import java.net.InetSocketAddress;
 import java.net.Socket;
+import java.util.ArrayList;
+import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
@@ -506,17 +510,18 @@
      * @throws InterruptedException If the thread is interrupted.
      */
     public void awaitPrivateDnsSetting(@NonNull String msg, @NonNull Network network,
-            @NonNull String server, boolean requiresValidatedServer) throws InterruptedException {
+            @Nullable String server, boolean requiresValidatedServer) throws InterruptedException {
         final CountDownLatch latch = new CountDownLatch(1);
         final NetworkRequest request = new NetworkRequest.Builder().clearCapabilities().build();
-        NetworkCallback callback = new NetworkCallback() {
+        final NetworkCallback callback = new NetworkCallback() {
             @Override
             public void onLinkPropertiesChanged(Network n, LinkProperties lp) {
                 Log.i(TAG, "Link properties of network " + n + " changed to " + lp);
                 if (requiresValidatedServer && lp.getValidatedPrivateDnsServers().isEmpty()) {
                     return;
                 }
-                if (network.equals(n) && server.equals(lp.getPrivateDnsServerName())) {
+                Log.i(TAG, "Set private DNS server to " + server);
+                if (network.equals(n) && Objects.equals(server, lp.getPrivateDnsServerName())) {
                     latch.countDown();
                 }
             }
@@ -539,6 +544,27 @@
     }
 
     /**
+     * Get all testable Networks with internet capability.
+     */
+    public Network[] getTestableNetworks() {
+        final ArrayList<Network> testableNetworks = new ArrayList<Network>();
+        for (Network network : mCm.getAllNetworks()) {
+            final NetworkCapabilities nc = mCm.getNetworkCapabilities(network);
+            if (nc != null
+                    && nc.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)
+                    && nc.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)) {
+                testableNetworks.add(network);
+            }
+        }
+
+        assertTrue("This test requires that at least one public Internet-providing"
+                        + " network be connected. Please ensure that the device is connected to"
+                        + " a network.",
+                testableNetworks.size() >= 1);
+        return testableNetworks.toArray(new Network[0]);
+    }
+
+    /**
      * Receiver that captures the last connectivity change's network type and state. Recognizes
      * both {@code CONNECTIVITY_ACTION} and {@code NETWORK_CALLBACK_ACTION} intents.
      */