My client has asked me to analyze his site. Now, I need the tool for analysis of negative aspects of external links. He wants to know what kind of links is pointing towards his site. He also wants to know if the site has any negative links. The problem is that I know how to look for links with Google’s back link search. Now the concern is that how do I know that these links have negative impact. The site has over five hundred external links. He wants to be warned of links from web spam sites/pages and known link brokers/sellers. Kindly share.