About Domain Name Servers For SEO



Theory is if you have a thousands spammy domains on one server (probably all crossed linked for popularity) and same whois - google may smack you. It could easily draw a flag that you're trying to manipulate the system. Ideally you want different hosting servers so it looks and feels more natural. That is the theory anyway.
 
About Domain Name Servers For SEO

Name servers are provided by your web hosting company.

They themselves are not that important. It it's the IP's, and different C-Classes you want in regards to SEO.

Long story short, you want it to make look like you have a bunch of relevant sites on different IP's linking to your main site. This is supposed to trick out the Google algo and give you higher relevancy in your targeted keywords and SERPS.

That is the short version.