I’ve done a little more benchmarking in the 127.0.0.1 vs. 0.0.0.0 issue:
<script>var start=new Date();</script> <script src="http://ad.a8.net/foo.js"></script> <script src="http://asy.a8ww.net/foo.js"></script> <script src="http://a9rhiwa.cn/foo.js"></script> <script src="http://www.a9rhiwa.cn/foo.js"></script> <script src="http://acezip.net/foo.js"></script> <script>var stop=new Date(); alert(stop.getTime() - start.getTime());</script>
- Firefox (3.5) showed no difference: the timing always was a couple of milliseconds
- Internet Explorer (8) and Google Chrome (2.0) showed quite a large difference in favor of 0.0.0.0: when using it, the pages constantly loaded in tens of milliseconds (between 0 and 30), while using 127.0.0.1 meant a page load time closer to a second (between 900 and 1500 milliseconds).
- Using Opera (9.64) the results were even further apart: the 0.0.0.0 case took ~1 second, while the 127.0.0.1 case took around 25 (!!!) seconds.
All the measurements were repeated multiple times to ensure their validity. The machine used for this test was running Windows XP with all the latest updates and without any webserver. IMHO this is yet an other argument in favor of using 0.0.0.0 instead of 127.0.0.1 when trying to block hosts.