diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index 709b774..1ab7515 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -229,7 +229,7 @@
      */
     protected void broadcastInterfaceStateChange(@NonNull String iface) {
         ensureRunningOnEthernetServiceThread();
-        final int state = mFactory.getInterfaceState(iface);
+        final int state = getInterfaceState(iface);
         final int role = getInterfaceRole(iface);
         final IpConfiguration config = getIpConfigurationForCallback(iface, state);
         final int n = mListeners.beginBroadcast();
@@ -436,15 +436,34 @@
         if (mDefaultInterface != null) {
             removeInterface(mDefaultInterface);
             addInterface(mDefaultInterface);
+            // when this broadcast is sent, any calls to notifyTetheredInterfaceAvailable or
+            // notifyTetheredInterfaceUnavailable have already happened
+            broadcastInterfaceStateChange(mDefaultInterface);
         }
     }
 
+    private int getInterfaceState(final String iface) {
+        if (mFactory.hasInterface(iface)) {
+            return mFactory.getInterfaceState(iface);
+        }
+        if (getInterfaceMode(iface) == INTERFACE_MODE_SERVER) {
+            // server mode interfaces are not tracked by the factory.
+            // TODO(b/234743836): interface state for server mode interfaces is not tracked
+            // properly; just return link up.
+            return EthernetManager.STATE_LINK_UP;
+        }
+        return EthernetManager.STATE_ABSENT;
+    }
+
     private int getInterfaceRole(final String iface) {
-        if (!mFactory.hasInterface(iface)) return EthernetManager.ROLE_NONE;
-        final int mode = getInterfaceMode(iface);
-        return (mode == INTERFACE_MODE_CLIENT)
-                ? EthernetManager.ROLE_CLIENT
-                : EthernetManager.ROLE_SERVER;
+        if (mFactory.hasInterface(iface)) {
+            // only client mode interfaces are tracked by the factory.
+            return EthernetManager.ROLE_CLIENT;
+        }
+        if (getInterfaceMode(iface) == INTERFACE_MODE_SERVER) {
+            return EthernetManager.ROLE_SERVER;
+        }
+        return EthernetManager.ROLE_NONE;
     }
 
     private int getInterfaceMode(final String iface) {
diff --git a/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java b/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
index 115f0e1..e90d55d 100644
--- a/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
+++ b/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
@@ -28,6 +28,7 @@
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.reset;
@@ -68,6 +69,7 @@
 
 import java.net.InetAddress;
 import java.util.ArrayList;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 @SmallTest
 @RunWith(AndroidJUnit4.class)
@@ -445,7 +447,20 @@
         when(mNetd.interfaceGetList()).thenReturn(new String[] {testIface});
         when(mNetd.interfaceGetCfg(eq(testIface))).thenReturn(ifaceParcel);
         doReturn(new String[] {testIface}).when(mFactory).getAvailableInterfaces(anyBoolean());
-        doReturn(EthernetManager.STATE_LINK_UP).when(mFactory).getInterfaceState(eq(testIface));
+
+        final AtomicBoolean ifaceUp = new AtomicBoolean(true);
+        doAnswer(inv -> ifaceUp.get()).when(mFactory).hasInterface(testIface);
+        doAnswer(inv ->
+                ifaceUp.get() ? EthernetManager.STATE_LINK_UP : EthernetManager.STATE_ABSENT)
+                .when(mFactory).getInterfaceState(testIface);
+        doAnswer(inv -> {
+            ifaceUp.set(true);
+            return null;
+        }).when(mFactory).addInterface(eq(testIface), eq(testHwAddr), any(), any());
+        doAnswer(inv -> {
+            ifaceUp.set(false);
+            return null;
+        }).when(mFactory).removeInterface(testIface);
 
         final EthernetStateListener listener = spy(new EthernetStateListener());
         tracker.addListener(listener, true /* canUseRestrictedNetworks */);
@@ -456,7 +471,6 @@
         verify(listener).onEthernetStateChanged(eq(EthernetManager.ETHERNET_STATE_ENABLED));
         reset(listener);
 
-        doReturn(EthernetManager.STATE_ABSENT).when(mFactory).getInterfaceState(eq(testIface));
         tracker.setEthernetEnabled(false);
         waitForIdle();
         verify(mFactory).removeInterface(eq(testIface));
@@ -465,7 +479,6 @@
                 anyInt(), any());
         reset(listener);
 
-        doReturn(EthernetManager.STATE_LINK_UP).when(mFactory).getInterfaceState(eq(testIface));
         tracker.setEthernetEnabled(true);
         waitForIdle();
         verify(mFactory).addInterface(eq(testIface), eq(testHwAddr), any(), any());