diff --git a/core/federated/federate.c b/core/federated/federate.c
index 3d3ea2c71..e2b2e5e72 100644
--- a/core/federated/federate.c
+++ b/core/federated/federate.c
@@ -284,6 +284,7 @@ static void update_last_known_status_on_input_port(environment_t* env, tag_t tag
     // federate that is far ahead of other upstream federates in logical time.
     lf_update_max_level(_fed.last_TAG, _fed.is_last_TAG_provisional);
     lf_cond_broadcast(&lf_port_status_changed);
+    lf_cond_broadcast(&env->event_q_changed);
   } else {
     // Message arrivals should be monotonic, so this should not occur.
     lf_print_warning("Attempt to update the last known status tag "
@@ -292,6 +293,34 @@ static void update_last_known_status_on_input_port(environment_t* env, tag_t tag
   }
 }
 
+/**
+ * @brief Mark all the input ports connected to the given federate as known to be absent until FOREVER.
+ *
+ * This does nothing if the federate is not using decentralized coordination.
+ * This function acquires the mutex on the top-level environment.
+ * @param fed_id The ID of the federate.
+ */
+static void mark_inputs_known_absent(int fed_id) {
+#ifdef FEDERATED_DECENTRALIZED
+  // Note that when transient federates are supported, this will need to be updated because the
+  // federate could rejoin.
+  environment_t* env;
+  _lf_get_environments(&env);
+  LF_MUTEX_LOCK(&env->mutex);
+
+  for (size_t i = 0; i < _lf_action_table_size; i++) {
+    lf_action_base_t* action = _lf_action_table[i];
+    if (action->source_id == fed_id) {
+      update_last_known_status_on_input_port(env, FOREVER_TAG, i);
+    }
+  }
+  LF_MUTEX_UNLOCK(&env->mutex);
+#else
+  // Do nothing, except suppress unused parameter error.
+  (void)fed_id;
+#endif // FEDERATED_DECENTRALIZED
+}
+
 /**
  * Set the status of network port with id portID.
  *
@@ -735,46 +764,46 @@ static void* listen_to_federates(void* _args) {
     bool socket_closed = false;
     // Read one byte to get the message type.
     LF_PRINT_DEBUG("Waiting for a P2P message on socket %d.", *socket_id);
+    bool bad_message = false;
     if (read_from_socket_close_on_error(socket_id, 1, buffer)) {
       // Socket has been closed.
       lf_print("Socket from federate %d is closed.", fed_id);
       // Stop listening to this federate.
       socket_closed = true;
-      break;
-    }
-    LF_PRINT_DEBUG("Received a P2P message on socket %d of type %d.", *socket_id, buffer[0]);
-    bool bad_message = false;
-    switch (buffer[0]) {
-    case MSG_TYPE_P2P_MESSAGE:
-      LF_PRINT_LOG("Received untimed message from federate %d.", fed_id);
-      if (handle_message(socket_id, fed_id)) {
-        // Failed to complete the reading of a message on a physical connection.
-        lf_print_warning("Failed to complete reading of message on physical connection.");
-        socket_closed = true;
-      }
-      break;
-    case MSG_TYPE_P2P_TAGGED_MESSAGE:
-      LF_PRINT_LOG("Received tagged message from federate %d.", fed_id);
-      if (handle_tagged_message(socket_id, fed_id)) {
-        // P2P tagged messages are only used in decentralized coordination, and
-        // it is not a fatal error if the socket is closed before the whole message is read.
-        // But this thread should exit.
-        lf_print_warning("Failed to complete reading of tagged message.");
-        socket_closed = true;
-      }
-      break;
-    case MSG_TYPE_PORT_ABSENT:
-      LF_PRINT_LOG("Received port absent message from federate %d.", fed_id);
-      if (handle_port_absent_message(socket_id, fed_id)) {
-        // P2P tagged messages are only used in decentralized coordination, and
-        // it is not a fatal error if the socket is closed before the whole message is read.
-        // But this thread should exit.
-        lf_print_warning("Failed to complete reading of tagged message.");
-        socket_closed = true;
+    } else {
+      LF_PRINT_DEBUG("Received a P2P message on socket %d of type %d.", *socket_id, buffer[0]);
+      switch (buffer[0]) {
+      case MSG_TYPE_P2P_MESSAGE:
+        LF_PRINT_LOG("Received untimed message from federate %d.", fed_id);
+        if (handle_message(socket_id, fed_id)) {
+          // Failed to complete the reading of a message on a physical connection.
+          lf_print_warning("Failed to complete reading of message on physical connection.");
+          socket_closed = true;
+        }
+        break;
+      case MSG_TYPE_P2P_TAGGED_MESSAGE:
+        LF_PRINT_LOG("Received tagged message from federate %d.", fed_id);
+        if (handle_tagged_message(socket_id, fed_id)) {
+          // P2P tagged messages are only used in decentralized coordination, and
+          // it is not a fatal error if the socket is closed before the whole message is read.
+          // But this thread should exit.
+          lf_print_warning("Failed to complete reading of tagged message.");
+          socket_closed = true;
+        }
+        break;
+      case MSG_TYPE_PORT_ABSENT:
+        LF_PRINT_LOG("Received port absent message from federate %d.", fed_id);
+        if (handle_port_absent_message(socket_id, fed_id)) {
+          // P2P tagged messages are only used in decentralized coordination, and
+          // it is not a fatal error if the socket is closed before the whole message is read.
+          // But this thread should exit.
+          lf_print_warning("Failed to complete reading of tagged message.");
+          socket_closed = true;
+        }
+        break;
+      default:
+        bad_message = true;
       }
-      break;
-    default:
-      bad_message = true;
     }
     if (bad_message) {
       lf_print_error("Received erroneous message type: %d. Closing the socket.", buffer[0]);
@@ -783,12 +812,10 @@ static void* listen_to_federates(void* _args) {
       break; // while loop
     }
     if (socket_closed) {
-      // NOTE: For decentralized execution, once this socket is closed, we could
+      // For decentralized execution, once this socket is closed, we
       // update last known tags of all ports connected to the specified federate to FOREVER_TAG,
       // which would eliminate the need to wait for STAA to assume an input is absent.
-      // However, at this time, we don't know which ports correspond to which upstream federates.
-      // The code generator would have to encode this information. Once that is done,
-      // we could call update_last_known_status_on_input_port with FOREVER_TAG.
+      mark_inputs_known_absent(fed_id);
 
       break; // while loop
     }
diff --git a/include/core/lf_types.h b/include/core/lf_types.h
index a3a103041..b6d754ca2 100644
--- a/include/core/lf_types.h
+++ b/include/core/lf_types.h
@@ -298,6 +298,7 @@ typedef struct {
   trigger_t* trigger; // THIS HAS TO MATCH lf_action_internal_t
   self_base_t* parent;
   bool has_value;
+  int source_id; // Used only for federated network input actions.
 } lf_action_base_t;
 
 /**
diff --git a/python/include/python_action.h b/python/include/python_action.h
index 880bfe149..f0682f9b5 100644
--- a/python/include/python_action.h
+++ b/python/include/python_action.h
@@ -61,6 +61,7 @@ typedef struct {
   lf_action_internal_t _base;
   self_base_t* parent;
   bool has_value;
+  int source_id;
   PyObject* value;
   FEDERATED_GENERIC_EXTENSION
 } generic_action_instance_struct;