If you do dofollow and high pr links you will get good results in serp. If you want to find nofollow link you can install this tool in your system if it is nofollow means it will show red colour dot line. install this tool addons.mozilla.org â€º Add-ons for Firefox â€º Extensions
Yes, both types of back link is necessary, if they generate in natural way. No follow back links does not crawl and index by SE robots, that's why that kind of back link does not passes link juice.
Do follow back links allow SE robots to crawl and index by SE robots, so that kind of back links passes link juice and increase SERP.
You can check your back link weather it is do follow or no follow by [URLnf="http://www.onlineseoanalyzer.com/Free-SEO-Tools/"]this tool[/URLnf].
According to me both the link get ran in search engine. we need some quality on our post.
When search engines rank websites, they look for external links pointing to other websites. If the link is â€œno followâ€, then search engines usually do not follow the link and â€œlink juiceâ€ might not get passed to the target link. Examples are links in Comments, Forums and Paid Links.
When search engines rank websites, they look for external links pointing to other websites. If the link is â€œdo followâ€, then search engines will follow the link and â€œlink juiceâ€ gets passed to the target link. The more â€œlink juiceâ€, the better it will be for the target link. Backlinks are DoFollow as a default.