struct sctp_chunk *chunk)
 {
        sctp_sender_hb_info_t *hbinfo;
+       int was_unconfirmed = 0;
 
        /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
         * HEARTBEAT should clear the error counter of the destination
        /* Mark the destination transport address as active if it is not so
         * marked.
         */
-       if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
+       if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
+               was_unconfirmed = 1;
                sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
                                             SCTP_HEARTBEAT_SUCCESS);
+       }
 
        /* The receiver of the HEARTBEAT ACK should also perform an
         * RTT measurement for that destination transport address
        /* Update the heartbeat timer.  */
        if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
                sctp_transport_hold(t);
+
+       if (was_unconfirmed && asoc->peer.transport_count == 1)
+               sctp_transport_immediate_rtx(t);
 }