diff --git a/tests/cts/net/Android.bp b/tests/cts/net/Android.bp
index 62f37bb..a6179fc 100644
--- a/tests/cts/net/Android.bp
+++ b/tests/cts/net/Android.bp
@@ -128,3 +128,18 @@
     ],
 }
 
+android_test {
+    name: "CtsNetTestCasesMaxTargetSdk30",  // Must match CtsNetTestCasesMaxTargetSdk30 annotation.
+    defaults: [
+        "CtsNetTestCasesDefaults",
+        "CtsNetTestCasesApiStableDefaults",
+    ],
+    target_sdk_version: "30",
+    package_name: "android.net.cts.maxtargetsdk30",  // CTS package names must be unique.
+    instrumentation_target_package: "android.net.cts.maxtargetsdk30",
+    test_suites: [
+        "cts",
+        "general-tests",
+        "mts-networking",
+    ],
+}
diff --git a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
index 64cc97d..a02be85 100644
--- a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
@@ -16,6 +16,7 @@
 package android.net.cts
 
 import android.Manifest.permission.MANAGE_TEST_NETWORKS
+import android.app.compat.CompatChanges
 import android.net.ConnectivityManager
 import android.net.ConnectivityManager.NetworkCallback
 import android.net.LinkProperties
@@ -46,6 +47,7 @@
 import android.net.nsd.NsdManager.RegistrationListener
 import android.net.nsd.NsdManager.ResolveListener
 import android.net.nsd.NsdServiceInfo
+import android.os.Build
 import android.os.Handler
 import android.os.HandlerThread
 import android.os.Process.myTid
@@ -56,17 +58,23 @@
 import com.android.net.module.util.ArrayTrackRecord
 import com.android.net.module.util.TrackRecord
 import com.android.networkstack.apishim.NsdShimImpl
+import com.android.testutils.ConnectivityModuleTest
+import com.android.testutils.DevSdkIgnoreRule
 import com.android.testutils.TestableNetworkAgent
 import com.android.testutils.TestableNetworkCallback
+import com.android.testutils.filters.CtsNetTestCasesMaxTargetSdk30
 import com.android.testutils.runAsShell
 import com.android.testutils.tryTest
 import org.junit.After
 import org.junit.Assert.assertArrayEquals
+import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
 import org.junit.Assume.assumeTrue
 import org.junit.Before
+import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
+import java.io.File
 import java.net.ServerSocket
 import java.nio.charset.StandardCharsets
 import java.util.Random
@@ -89,6 +97,10 @@
 @AppModeFull(reason = "Socket cannot bind in instant app mode")
 @RunWith(AndroidJUnit4::class)
 class NsdManagerTest {
+    // Rule used to filter CtsNetTestCasesMaxTargetSdkXX
+    @get:Rule
+    val ignoreRule = DevSdkIgnoreRule()
+
     private val context by lazy { InstrumentationRegistry.getInstrumentation().context }
     private val nsdManager by lazy { context.getSystemService(NsdManager::class.java) }
 
@@ -692,6 +704,30 @@
         }
     }
 
+    @Test @CtsNetTestCasesMaxTargetSdk30("Socket is started with the service up to target SDK 30")
+    fun testManagerCreatesLegacySocket() {
+        nsdManager // Ensure the lazy-init member is initialized, so NsdManager is created
+        val socket = File("/dev/socket/mdnsd")
+        val timeout = System.currentTimeMillis() + TIMEOUT_MS
+        while (!socket.exists() && System.currentTimeMillis() < timeout) {
+            Thread.sleep(10)
+        }
+        assertTrue("$socket was not found after $TIMEOUT_MS ms", socket.exists())
+    }
+
+    // The compat change is part of a connectivity module update that applies to T+
+    @ConnectivityModuleTest @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    @Test @CtsNetTestCasesMaxTargetSdk30("Socket is started with the service up to target SDK 30")
+    fun testManagerCreatesLegacySocket_CompatChange() {
+        // The socket may have been already created by some other app, or some other test, in which
+        // case this test cannot verify creation. At least verify that the compat change is
+        // disabled in a process with max SDK 30; unit tests already verify that start is requested
+        // when the compat change is disabled.
+        // Note that before T the compat constant had a different int value.
+        assertFalse(CompatChanges.isChangeEnabled(
+                NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS_T_AND_LATER))
+    }
+
     /**
      * Register a service and return its registration record.
      */