anchor.diff:      ok = gen_tcp:controlling_process(Socket, Pid),
       gen_fsm:send_event(Pid, {accepted, Socket}).
   
  -tun_in(<< 16#6:4, _Class:8, _Flow:20, Len:16, _Next:8, _Hop:8, _Src:128,
  -	  Dst:16/binary,
  +tun_in(<< 16#6:4, _Class:8, _Flow:20, Len:16, _Next:8, _Hop:8,
  +	  ?Prefix:48, _Src:80, ?Prefix:48, Dst:80,
   	  _Data:Len/binary >> = Pkt) ->
       case erl_ocat_reg:lookup(Dst) of
   	undefined ->
  
positive.code: 	false -> {stop, normal, State};
  	true -> tcp_data1(Len, Frag, Bin, State#s{fd = FD})
      end;
  tcp_data(Frag, StateName, #s{} = State) ->
      next_state(StateName, State#s{frag = Frag}).
  
  
negative.code: 
  -define(IPv6_HEADER_SIZE, 40).
  
  %% FD60:DB4D:DDB5::/48
  %%-define(Prefix, 16#FD60DB4DDDB5).
  
  %% fd87:d87e:eb43::/48
  -define(Prefix, 16#fd87d87eeb43).
  
  -record(s, {socket, frag = <<>>, fd}).
  
  accepted(Socket) ->
  