diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index 9c8fd99..71f289e 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -131,6 +131,10 @@
     // returned when a tethered interface is requested; until then, it remains in client mode. Its
     // current mode is reflected in mTetheringInterfaceMode.
     private String mTetheringInterface;
+    // If the tethering interface is in server mode, it is not tracked by factory. The HW address
+    // must be maintained by the EthernetTracker. Its current mode is reflected in
+    // mTetheringInterfaceMode.
+    private String mTetheringInterfaceHwAddr;
     private int mTetheringInterfaceMode = INTERFACE_MODE_CLIENT;
     // Tracks whether clients were notified that the tethered interface is available
     private boolean mTetheredInterfaceWasAvailable = false;
@@ -582,6 +586,7 @@
         removeInterface(iface);
         if (iface.equals(mTetheringInterface)) {
             mTetheringInterface = null;
+            mTetheringInterfaceHwAddr = null;
         }
         broadcastInterfaceStateChange(iface);
     }
@@ -610,13 +615,14 @@
             return;
         }
 
+        final String hwAddress = config.hwAddr;
+
         if (getInterfaceMode(iface) == INTERFACE_MODE_SERVER) {
             maybeUpdateServerModeInterfaceState(iface, true);
+            mTetheringInterfaceHwAddr = hwAddress;
             return;
         }
 
-        final String hwAddress = config.hwAddr;
-
         NetworkCapabilities nc = mNetworkCapabilities.get(iface);
         if (nc == null) {
             // Try to resolve using mac address