anchor.diff:                         (tcp-listener-backlog listener))))
              (when (tcp-listener-backlog listener)
                (incf (tcp-listener-n-pending-connections listener)))
  -           (let* ((rcv-seq (+u32 (ub32ref/be packet (+ start +tcp4-header-sequence-number+)) 1))
  -                  (snd-seq (random #x100000000))
  +           (let* ((irs (ub32ref/be packet (+ start +tcp4-header-sequence-number+)))
  +                  (iss (random #x100000000))
                     (connection (make-instance 'tcp-connection
                                                :state :syn-received
                                                :local-port local-port
                                                :local-ip local-ip
                                                :remote-port remote-port
                                                :remote-ip remote-ip
  -                                             :snd.nxt (+u32 snd-seq 1)
  -                                             :rcv.nxt rcv-seq
  +                                             :snd.nxt (+u32 iss 1)
  +                                             :rcv.nxt (+u32 irs 1)
                                                :rcv.wnd *initial-window-size*
                                                :boot-id (mezzano.supervisor:current-boot-id))))
                (mezzano.supervisor:with-mutex (*tcp-connection-lock*)
  
positive.code:   (let* ((interface (nth-value 1 (mezzano.network.ip:ipv4-route ip)))
           (source-address (mezzano.network.ip:ipv4-interface-address interface))
           (source-port (allocate-local-tcp-port source-address ip port))
           (seq (random #x100000000))
           (connection (make-instance 'tcp-connection
                                      :state :syn-sent
                                      :local-port source-port
                                      :local-ip source-address
                                      :remote-port port
                                      :remote-ip ip
                                      :snd.nxt (+u32 seq 1)
                                      :rcv.nxt 0
                                      :rcv.wnd *initial-window-size*
                                      :boot-id (if persist nil (mezzano.supervisor:current-boot-id)))))
  
negative.code:              (setf (gethash connection (tcp-listener-pending-connections listener))
                     connection)
               (when (not *netmangler-force-local-retransmit*)
                 (tcp4-send-packet connection iss (+u32 irs 1) nil :ack-p t :syn-p t)))))))
  
  (defun tcp4-accept-connection (connection &key element-type external-format)
    (cond ((or (not element-type)
  