anchor.diff:  
   find_real_ip([_|R], Type) ->
       find_real_ip(R, Type).
  -
  -
  -% %% @doc Normalizes a IPv6 in case of a fe80 address
  -% -spec normalize_ipv6({{inet:ipv6_address(), string()}}) ->
  -%     binary().
  -
  -% normalize_ipv6({{65152, _, _, _, _, _, _, _}=Ip, Iface}) -> 
  -%     list_to_binary([$[, inet_parse:ntoa(Ip), $%, Iface, $]]);
  -
  -% normalize_ipv6({{_, _, _, _, _, _, _, _}=Ip, _Iface}) -> 
  -%     list_to_binary([$[, inet_parse:ntoa(Ip), $]]).
  -
   
   
   % calendar:datetime_to_gregorian_seconds({{1970,1,1},{0,0,0}}).
  
positive.code:     {ok, All} = inet:getifaddrs(),
      case NetInterface of
          auto ->
              IFaces = ["eth0", "eth1", "en0", "en1" | proplists:get_keys(All)],
              find_main_ip(IFaces, All, Type);
          _ ->
              find_main_ip([NetInterface], All, Type)   
      end.
  
negative.code: 
  %% @doc Finds the <i>best</i> local IP.
  %% If a network interface is supplied (as "en0") it returns its ip.
  %% If `auto' is used, probes `ethX' and `enX' interfaces. If none is available returns 
  %% localhost
  -spec find_main_ip(auto|string(), ipv4|ipv6) -> 
      inet:ip_address().
  
  