Description:
------------
As per RFC3330: http://tools.ietf.org/html/rfc3330

   128.0.0.0/16 - This block, corresponding to the numerically lowest of
   the former Class B addresses, was initially and is still reserved by
   the IANA.  Given the present classless nature of the IP address
   space, the basis for the reservation no longer applies and addresses
   in this block are subject to future allocation to a Regional Internet
   Registry for assignment in the normal manner.

however,

https://github.com/php/php-src/blob/master/ext/filter/logical_filters.c#L718

still tests for 128.0.x.x

Test script:
---------------
$valid = filter_var( '128.0.46.45', FILTER_VALIDATE_IP, FILTER_FLAG_NO_RES_RANGE );


Expected result:
----------------
$valid === '128.0.46.45';

Actual result:
--------------
$valid === false;