anchor.diff:                        (setf (tcp-connection-state connection) :closed)
                         (detach-tcp-connection connection))
                        ((logtest flags +tcp4-flag-fin+)
  +                      ;; Simultaneous close
                         (tcp4-send-packet connection
                                           (tcp-connection-s-next connection)
                                           (tcp-connection-r-next connection)
  
positive.code:                                         nil
                                          :ack-p t))
                       ;; Ignore future out-of-order packets, should be managed instead.
                       (t (format t "TCP state :established. ~
                                     Ignoring future packet with sequence number ~D, wanted <= ~D.~%"
                                  seq (tcp-connection-r-next connection)))))))
          (:fin-wait-2
  
negative.code:          (if (zerop data-length)
               (when (= seq (tcp-connection-r-next connection))
                 (cond ((logtest flags +tcp4-flag-fin+)
                        ;; Remote have sended FIN and waiting for ACK
                        (setf (tcp-connection-state connection) :close-wait
                              (tcp-connection-r-next connection)
                              (logand (+ (tcp-connection-r-next connection) 1)
  