The ColdLink iis isapi filter or apache module transparently maps and rewrites protected urls dynamically in realtime within every page served from your site. The ColdLink iis isapi filter or apache module transparently maps and rewrites protected urls dynamically in realtime within every page served from your site. Your site continues to work normally, even when the pages are linked from search engines or other sites. Users can even bookmark your pages for later return because the page will contain new valid links.