diff --git a/framework/src/android/net/ConnectivitySettingsManager.java b/framework/src/android/net/ConnectivitySettingsManager.java
index 03c3600..4644e4f 100644
--- a/framework/src/android/net/ConnectivitySettingsManager.java
+++ b/framework/src/android/net/ConnectivitySettingsManager.java
@@ -20,12 +20,13 @@
 import static android.net.ConnectivityManager.MULTIPATH_PREFERENCE_PERFORMANCE;
 import static android.net.ConnectivityManager.MULTIPATH_PREFERENCE_RELIABILITY;
 
+import static com.android.net.module.util.ConnectivitySettingsUtils.getPrivateDnsModeAsString;
+
 import android.annotation.IntDef;
 import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
-import android.content.ContentResolver;
 import android.content.Context;
 import android.net.ConnectivityManager.MultipathPreference;
 import android.os.Process;
@@ -35,6 +36,7 @@
 import android.util.ArraySet;
 import android.util.Range;
 
+import com.android.net.module.util.ConnectivitySettingsUtils;
 import com.android.net.module.util.ProxyUtils;
 
 import java.lang.annotation.Retention;
@@ -345,20 +347,22 @@
     /**
      * One of the private DNS modes that indicates the private DNS mode is off.
      */
-    public static final int PRIVATE_DNS_MODE_OFF = 1;
+    public static final int PRIVATE_DNS_MODE_OFF = ConnectivitySettingsUtils.PRIVATE_DNS_MODE_OFF;
 
     /**
      * One of the private DNS modes that indicates the private DNS mode is automatic, which
      * will try to use the current DNS as private DNS.
      */
-    public static final int PRIVATE_DNS_MODE_OPPORTUNISTIC = 2;
+    public static final int PRIVATE_DNS_MODE_OPPORTUNISTIC =
+            ConnectivitySettingsUtils.PRIVATE_DNS_MODE_OPPORTUNISTIC;
 
     /**
      * One of the private DNS modes that indicates the private DNS mode is strict and the
      * {@link #PRIVATE_DNS_SPECIFIER} is required, which will try to use the value of
      * {@link #PRIVATE_DNS_SPECIFIER} as private DNS.
      */
-    public static final int PRIVATE_DNS_MODE_PROVIDER_HOSTNAME = 3;
+    public static final int PRIVATE_DNS_MODE_PROVIDER_HOSTNAME =
+            ConnectivitySettingsUtils.PRIVATE_DNS_MODE_PROVIDER_HOSTNAME;
 
     /** @hide */
     @Retention(RetentionPolicy.SOURCE)
@@ -369,10 +373,6 @@
     })
     public @interface PrivateDnsMode {}
 
-    private static final String PRIVATE_DNS_MODE_OFF_STRING = "off";
-    private static final String PRIVATE_DNS_MODE_OPPORTUNISTIC_STRING = "opportunistic";
-    private static final String PRIVATE_DNS_MODE_PROVIDER_HOSTNAME_STRING = "hostname";
-
     /**
      * A list of uids that is allowed to use restricted networks.
      *
@@ -730,32 +730,6 @@
                 context.getContentResolver(), GLOBAL_HTTP_PROXY_PAC, "" /* value */);
     }
 
-    private static String getPrivateDnsModeAsString(@PrivateDnsMode int mode) {
-        switch (mode) {
-            case PRIVATE_DNS_MODE_OFF:
-                return PRIVATE_DNS_MODE_OFF_STRING;
-            case PRIVATE_DNS_MODE_OPPORTUNISTIC:
-                return PRIVATE_DNS_MODE_OPPORTUNISTIC_STRING;
-            case PRIVATE_DNS_MODE_PROVIDER_HOSTNAME:
-                return PRIVATE_DNS_MODE_PROVIDER_HOSTNAME_STRING;
-            default:
-                throw new IllegalArgumentException("Invalid private dns mode: " + mode);
-        }
-    }
-
-    private static int getPrivateDnsModeAsInt(String mode) {
-        switch (mode) {
-            case "off":
-                return PRIVATE_DNS_MODE_OFF;
-            case "hostname":
-                return PRIVATE_DNS_MODE_PROVIDER_HOSTNAME;
-            case "opportunistic":
-                return PRIVATE_DNS_MODE_OPPORTUNISTIC;
-            default:
-                throw new IllegalArgumentException("Invalid private dns mode: " + mode);
-        }
-    }
-
     /**
      * Get private DNS mode from settings.
      *
@@ -764,13 +738,7 @@
      */
     @PrivateDnsMode
     public static int getPrivateDnsMode(@NonNull Context context) {
-        final ContentResolver cr = context.getContentResolver();
-        String mode = Settings.Global.getString(cr, PRIVATE_DNS_MODE);
-        if (TextUtils.isEmpty(mode)) mode = Settings.Global.getString(cr, PRIVATE_DNS_DEFAULT_MODE);
-        // If both PRIVATE_DNS_MODE and PRIVATE_DNS_DEFAULT_MODE are not set, choose
-        // PRIVATE_DNS_MODE_OPPORTUNISTIC as default mode.
-        if (TextUtils.isEmpty(mode)) return PRIVATE_DNS_MODE_OPPORTUNISTIC;
-        return getPrivateDnsModeAsInt(mode);
+        return ConnectivitySettingsUtils.getPrivateDnsMode(context);
     }
 
     /**
@@ -780,13 +748,7 @@
      * @param mode The private dns mode. This should be one of the PRIVATE_DNS_MODE_* constants.
      */
     public static void setPrivateDnsMode(@NonNull Context context, @PrivateDnsMode int mode) {
-        if (!(mode == PRIVATE_DNS_MODE_OFF
-                || mode == PRIVATE_DNS_MODE_OPPORTUNISTIC
-                || mode == PRIVATE_DNS_MODE_PROVIDER_HOSTNAME)) {
-            throw new IllegalArgumentException("Invalid private dns mode: " + mode);
-        }
-        Settings.Global.putString(context.getContentResolver(), PRIVATE_DNS_MODE,
-                getPrivateDnsModeAsString(mode));
+        ConnectivitySettingsUtils.setPrivateDnsMode(context, mode);
     }
 
     /**
@@ -797,7 +759,7 @@
      */
     @Nullable
     public static String getPrivateDnsHostname(@NonNull Context context) {
-        return Settings.Global.getString(context.getContentResolver(), PRIVATE_DNS_SPECIFIER);
+        return ConnectivitySettingsUtils.getPrivateDnsHostname(context);
     }
 
     /**
@@ -806,9 +768,8 @@
      * @param context The {@link Context} to set the setting.
      * @param specifier The specific private dns provider name.
      */
-    public static void setPrivateDnsHostname(@NonNull Context context,
-            @Nullable String specifier) {
-        Settings.Global.putString(context.getContentResolver(), PRIVATE_DNS_SPECIFIER, specifier);
+    public static void setPrivateDnsHostname(@NonNull Context context, @Nullable String specifier) {
+        ConnectivitySettingsUtils.setPrivateDnsHostname(context, specifier);
     }
 
     /**
diff --git a/tests/cts/net/util/Android.bp b/tests/cts/net/util/Android.bp
index b5f1208..fffd30f 100644
--- a/tests/cts/net/util/Android.bp
+++ b/tests/cts/net/util/Android.bp
@@ -27,5 +27,6 @@
         "junit",
         "net-tests-utils",
         "modules-utils-build",
+        "net-utils-framework-common",
     ],
 }
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 4abbecc..bce9880 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
@@ -56,12 +56,13 @@
 import android.os.Binder;
 import android.os.Build;
 import android.os.IBinder;
-import android.provider.Settings;
 import android.system.Os;
 import android.system.OsConstants;
+import android.text.TextUtils;
 import android.util.Log;
 
 import com.android.compatibility.common.util.SystemUtil;
+import com.android.net.module.util.ConnectivitySettingsUtils;
 
 import junit.framework.AssertionFailedError;
 
@@ -80,7 +81,6 @@
 
 public final class CtsNetUtils {
     private static final String TAG = CtsNetUtils.class.getSimpleName();
-    private static final int DURATION = 10000;
     private static final int SOCKET_TIMEOUT_MS = 2000;
     private static final int PRIVATE_DNS_PROBE_MS = 1_000;
 
@@ -104,7 +104,7 @@
     private final ContentResolver mCR;
     private final WifiManager mWifiManager;
     private TestNetworkCallback mCellNetworkCallback;
-    private String mOldPrivateDnsMode;
+    private int mOldPrivateDnsMode = 0;
     private String mOldPrivateDnsSpecifier;
 
     public CtsNetUtils(Context context) {
@@ -508,64 +508,69 @@
     }
 
     public void storePrivateDnsSetting() {
-        // Store private DNS setting
-        mOldPrivateDnsMode = Settings.Global.getString(mCR, Settings.Global.PRIVATE_DNS_MODE);
-        mOldPrivateDnsSpecifier = Settings.Global.getString(mCR,
-                Settings.Global.PRIVATE_DNS_SPECIFIER);
-        // It's possible that there is no private DNS default value in Settings.
-        // Give it a proper default mode which is opportunistic mode.
-        if (mOldPrivateDnsMode == null) {
-            mOldPrivateDnsSpecifier = "";
-            mOldPrivateDnsMode = PRIVATE_DNS_MODE_OPPORTUNISTIC;
-            Settings.Global.putString(mCR,
-                    Settings.Global.PRIVATE_DNS_SPECIFIER, mOldPrivateDnsSpecifier);
-            Settings.Global.putString(mCR, Settings.Global.PRIVATE_DNS_MODE, mOldPrivateDnsMode);
-        }
+        mOldPrivateDnsMode = ConnectivitySettingsUtils.getPrivateDnsMode(mContext);
+        mOldPrivateDnsSpecifier = ConnectivitySettingsUtils.getPrivateDnsHostname(mContext);
     }
 
     public void restorePrivateDnsSetting() throws InterruptedException {
-        if (mOldPrivateDnsMode == null) {
+        if (mOldPrivateDnsMode == 0) {
             fail("restorePrivateDnsSetting without storing settings first");
         }
-        // restore private DNS setting
-        if (PRIVATE_DNS_MODE_STRICT.equals(mOldPrivateDnsMode)) {
-            // In case of invalid setting, set to opportunistic to avoid a bad state and fail
-            if (mOldPrivateDnsSpecifier == null) {
-                Settings.Global.putString(mCR, Settings.Global.PRIVATE_DNS_MODE,
-                        PRIVATE_DNS_MODE_OPPORTUNISTIC);
-                fail("Invalid private DNS setting: no hostname specified in strict mode");
-            }
-            setPrivateDnsStrictMode(mOldPrivateDnsSpecifier);
 
-            awaitPrivateDnsSetting("restorePrivateDnsSetting timeout",
-                    mCm.getActiveNetwork(),
-                    mOldPrivateDnsSpecifier, true);
-        } else {
-            Settings.Global.putString(mCR, Settings.Global.PRIVATE_DNS_MODE, mOldPrivateDnsMode);
+        if (mOldPrivateDnsMode != ConnectivitySettingsUtils.PRIVATE_DNS_MODE_PROVIDER_HOSTNAME) {
+            ConnectivitySettingsUtils.setPrivateDnsMode(mContext, mOldPrivateDnsMode);
+            return;
         }
+        // restore private DNS setting
+        // In case of invalid setting, set to opportunistic to avoid a bad state and fail
+        if (TextUtils.isEmpty(mOldPrivateDnsSpecifier)) {
+            ConnectivitySettingsUtils.setPrivateDnsMode(mContext,
+                    ConnectivitySettingsUtils.PRIVATE_DNS_MODE_OPPORTUNISTIC);
+            fail("Invalid private DNS setting: no hostname specified in strict mode");
+        }
+        setPrivateDnsStrictMode(mOldPrivateDnsSpecifier);
+
+        // There might be a race before private DNS setting is applied and the next test is
+        // running. So waiting private DNS to be validated can reduce the flaky rate of test.
+        awaitPrivateDnsSetting("restorePrivateDnsSetting timeout",
+                mCm.getActiveNetwork(),
+                mOldPrivateDnsSpecifier, true /* requiresValidatedServer */);
     }
 
     public void setPrivateDnsStrictMode(String server) {
         // To reduce flake rate, set PRIVATE_DNS_SPECIFIER before PRIVATE_DNS_MODE. This ensures
         // that if the previous private DNS mode was not strict, the system only sees one
         // EVENT_PRIVATE_DNS_SETTINGS_CHANGED event instead of two.
-        Settings.Global.putString(mCR, Settings.Global.PRIVATE_DNS_SPECIFIER, server);
-        final String mode = Settings.Global.getString(mCR, Settings.Global.PRIVATE_DNS_MODE);
+        ConnectivitySettingsUtils.setPrivateDnsHostname(mContext, server);
+        final int mode = ConnectivitySettingsUtils.getPrivateDnsMode(mContext);
         // If current private DNS mode is strict, we only need to set PRIVATE_DNS_SPECIFIER.
-        if (!PRIVATE_DNS_MODE_STRICT.equals(mode)) {
-            Settings.Global.putString(mCR, Settings.Global.PRIVATE_DNS_MODE,
-                    PRIVATE_DNS_MODE_STRICT);
+        if (mode != ConnectivitySettingsUtils.PRIVATE_DNS_MODE_PROVIDER_HOSTNAME) {
+            ConnectivitySettingsUtils.setPrivateDnsMode(mContext,
+                    ConnectivitySettingsUtils.PRIVATE_DNS_MODE_PROVIDER_HOSTNAME);
         }
     }
 
+    /**
+     * Waiting for the new private DNS setting to be validated.
+     * This method is helpful when the new private DNS setting is configured and ensure the new
+     * setting is applied and workable. It can also reduce the flaky rate when the next test is
+     * running.
+     *
+     * @param msg A message that will be printed when the validation of private DNS is timeout.
+     * @param network A network which will apply the new private DNS setting.
+     * @param server The hostname of private DNS.
+     * @param requiresValidatedServer A boolean to decide if it's needed to wait private DNS to be
+     *                                 validated or not.
+     * @throws InterruptedException If the thread is interrupted.
+     */
     public void awaitPrivateDnsSetting(@NonNull String msg, @NonNull Network network,
-            @NonNull String server, boolean requiresValidatedServers) throws InterruptedException {
-        CountDownLatch latch = new CountDownLatch(1);
-        NetworkRequest request = new NetworkRequest.Builder().clearCapabilities().build();
+            @NonNull String server, boolean requiresValidatedServer) throws InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(1);
+        final NetworkRequest request = new NetworkRequest.Builder().clearCapabilities().build();
         NetworkCallback callback = new NetworkCallback() {
             @Override
             public void onLinkPropertiesChanged(Network n, LinkProperties lp) {
-                if (requiresValidatedServers && lp.getValidatedPrivateDnsServers().isEmpty()) {
+                if (requiresValidatedServer && lp.getValidatedPrivateDnsServers().isEmpty()) {
                     return;
                 }
                 if (network.equals(n) && server.equals(lp.getPrivateDnsServerName())) {
@@ -585,7 +590,7 @@
         // private DNS probe. There is no way to know when the probe has completed: because the
         // network is likely already validated, there is no callback that we can listen to, so
         // just sleep.
-        if (requiresValidatedServers) {
+        if (requiresValidatedServer) {
             Thread.sleep(PRIVATE_DNS_PROBE_MS);
         }
     }