diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
index 49442a6..f8169cb 100644
--- a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
@@ -905,10 +905,16 @@
 
         if (forwardingPairExists(intIface, extIface)) return;
 
+        boolean firstUpstreamForThisDownstream = !isAnyForwardingPairOnDownstream(intIface);
         boolean firstDownstreamForThisUpstream = !isAnyForwardingPairOnUpstream(extIface);
         forwardingPairAdd(intIface, extIface);
 
-        mBpfCoordinatorShim.attachProgram(intIface, UPSTREAM);
+        // Attach if the downstream is the first time to be used in a forwarding pair.
+        // Ex: IPv6 only interface has two forwarding pair, iface and v4-iface, on the
+        // same downstream.
+        if (firstUpstreamForThisDownstream) {
+            mBpfCoordinatorShim.attachProgram(intIface, UPSTREAM);
+        }
         // Attach if the upstream is the first time to be used in a forwarding pair.
         if (firstDownstreamForThisUpstream) {
             mBpfCoordinatorShim.attachProgram(extIface, DOWNSTREAM);
@@ -922,7 +928,9 @@
         forwardingPairRemove(intIface, extIface);
 
         // Detaching program may fail because the interface has been removed already.
-        mBpfCoordinatorShim.detachProgram(intIface);
+        if (!isAnyForwardingPairOnDownstream(intIface)) {
+            mBpfCoordinatorShim.detachProgram(intIface);
+        }
         // Detach if no more forwarding pair is using the upstream.
         if (!isAnyForwardingPairOnUpstream(extIface)) {
             mBpfCoordinatorShim.detachProgram(extIface);
@@ -1827,6 +1835,13 @@
         return mForwardingPairs.containsKey(extIface);
     }
 
+    private boolean isAnyForwardingPairOnDownstream(@NonNull String intIface) {
+        for (final HashSet downstreams : mForwardingPairs.values()) {
+            if (downstreams.contains(intIface)) return true;
+        }
+        return false;
+    }
+
     @NonNull
     private NetworkStats buildNetworkStats(@NonNull StatsType type, int ifIndex,
             @NonNull final ForwardedStats diff) {
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
index fa1d881..788673a 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
@@ -1277,47 +1277,62 @@
         try {
             final String intIface1 = "wlan1";
             final String intIface2 = "rndis0";
-            final String extIface = "rmnet_data0";
+            final String extIface1 = "rmnet_data0";
+            final String extIface2 = "v4-rmnet_data0";
             final String virtualIface = "ipsec0";
             final BpfUtils mockMarkerBpfUtils = staticMockMarker(BpfUtils.class);
             final BpfCoordinator coordinator = makeBpfCoordinator();
 
             // [1] Add the forwarding pair <wlan1, rmnet_data0>. Expect that attach both wlan1 and
             // rmnet_data0.
-            coordinator.maybeAttachProgram(intIface1, extIface);
-            ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface, DOWNSTREAM));
+            coordinator.maybeAttachProgram(intIface1, extIface1);
+            ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface1, DOWNSTREAM));
             ExtendedMockito.verify(() -> BpfUtils.attachProgram(intIface1, UPSTREAM));
             ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
             ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
 
             // [2] Add the forwarding pair <wlan1, rmnet_data0> again. Expect no more action.
-            coordinator.maybeAttachProgram(intIface1, extIface);
+            coordinator.maybeAttachProgram(intIface1, extIface1);
             ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
             ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
 
             // [3] Add the forwarding pair <rndis0, rmnet_data0>. Expect that attach rndis0 only.
-            coordinator.maybeAttachProgram(intIface2, extIface);
+            coordinator.maybeAttachProgram(intIface2, extIface1);
             ExtendedMockito.verify(() -> BpfUtils.attachProgram(intIface2, UPSTREAM));
             ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
             ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
 
-            // [4] Remove the forwarding pair <rndis0, rmnet_data0>. Expect detach rndis0 only.
-            coordinator.maybeDetachProgram(intIface2, extIface);
+            // [4] Add the forwarding pair <rndis0, v4-rmnet_data0>. Expect that attach
+            // v4-rmnet_data0 only.
+            coordinator.maybeAttachProgram(intIface2, extIface2);
+            ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface2, DOWNSTREAM));
+            ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
+            ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
+
+            // [5] Remove the forwarding pair <rndis0, v4-rmnet_data0>. Expect detach
+            // v4-rmnet_data0 only.
+            coordinator.maybeDetachProgram(intIface2, extIface2);
+            ExtendedMockito.verify(() -> BpfUtils.detachProgram(extIface2));
+            ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
+            ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
+
+            // [6] Remove the forwarding pair <rndis0, rmnet_data0>. Expect detach rndis0 only.
+            coordinator.maybeDetachProgram(intIface2, extIface1);
             ExtendedMockito.verify(() -> BpfUtils.detachProgram(intIface2));
             ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
             ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
 
-            // [5] Remove the forwarding pair <wlan1, rmnet_data0>. Expect that detach both wlan1
+            // [7] Remove the forwarding pair <wlan1, rmnet_data0>. Expect that detach both wlan1
             // and rmnet_data0.
-            coordinator.maybeDetachProgram(intIface1, extIface);
-            ExtendedMockito.verify(() -> BpfUtils.detachProgram(extIface));
+            coordinator.maybeDetachProgram(intIface1, extIface1);
+            ExtendedMockito.verify(() -> BpfUtils.detachProgram(extIface1));
             ExtendedMockito.verify(() -> BpfUtils.detachProgram(intIface1));
             ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
             ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
 
-            // [6] Skip attaching if upstream is virtual interface.
+            // [8] Skip attaching if upstream is virtual interface.
             coordinator.maybeAttachProgram(intIface1, virtualIface);
-            ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface, DOWNSTREAM), never());
+            ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface1, DOWNSTREAM), never());
             ExtendedMockito.verify(() -> BpfUtils.attachProgram(intIface1, UPSTREAM), never());
             ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
             ExtendedMockito.clearInvocations(mockMarkerBpfUtils);