UA: Mozilla/5.0 (compatible; Lipperhey Link Explorer;
This is not a "link checker" per sey. It seems to be a tool that finds incoming links to your site, then suggests a link strategy built from sites in their database. Another one of those making money off your content schemes.
Server Farm: WideXS, Netherlands
184.108.40.206 - 220.127.116.11
However tLipperhey offers software, so these data mining crawls may come from any IP address of any machine running this program.
Older Thread: [webmasterworld.com