I have 2 questions: 1) Are sub-domains considered internal or external links? 2) I have a lot of sub-domains (over 1000) with a link back to the main site. Google has finally recognized these backlinks & my backlink count in google has increased. But i read somewhere that google doesn't like too many backlinks from sites with same IP. Are these backlinks from my sub-domains going to be an issue in the long run?
You're running a high risk of getting banned from google with that many backlinks on one IP. I wouldn't have more than 5 or 10 backlinks from the same IP.
you mean to say that subdomains linking to the main site DOES have importance for link building but should not be much. Right? There are many websites that provides free hosting space (subdomains) with a single link in the bottom (linking to the main site). These sites gets many links from the website's subdomains and from the same IP. how are all these managed?
i think its an mather of balance if you have 10 backlinks and 9 are from the same ip then you obviously are at high risk. however if you have 10k backlinks and 9 from the same ip then you probably are at low risk
dont listen to any of the above, i run a free blog hosting site and when a user signs up they get a free subdomain URL and each of them link back to the main URL, i have thousands of hosted accounts and the main site is PR5 and has never had any penalties or ban. hope that answers your question