anchor.diff:      try
           Ip = yaws_logger_netutils:parse_ip(HostName),
           format_real_ip(Ip, InH, RevPx)
  +    catch
  +        _:_ ->
  +            HostName
  +    end.
  +
  +format_real_host(Ip, InH, RevPx) when is_tuple(Ip) ->
  +    case is_whitelisted_revproxy(Ip, RevPx) of
  +        true ->
  +            case yaws:split_sep(InH#headers.x_forwarded_for, $,) of
  +                [FirstIp|_Proxies] -> format_host(FirstIp);
  +                []                 -> format_host(Ip)
  +            end;
  +        false ->
  +            format_host(Ip)
  +    end;
  +format_real_host(unknown, _InH, _RevPx) ->
  +    "unknown";
  +format_real_host(undefined, _InH, _RevPx) ->
  +    "unknown";
  +format_real_host(HostName, InH, RevPx) ->
  +    try
  +        Ip = yaws_logger_netutils:parse_ip(HostName),
  +        format_real_host(Ip, InH, RevPx)
       catch
           _:_ ->
               HostName
  
positive.code:                  {Ip,_,_,OutH,_}=Data, Msg) ->
      Msg1 = case check_cond(Cond, OutH#outh.status) of
                 true  -> [format_host(Ip)|Msg];
                 false -> [$-|Msg]
             end,
      format_accesslog(Rest, ServerName, RevPx, Data, Msg1);
  
negative.code:     HostName.
  
  
  format_host(Ip) when is_tuple(Ip); is_list(Ip) ->
      case inet:gethostbyaddr(Ip) of
          {ok, H} -> element(2, H);
  