How search engines see reciprocal links?

Question

Reciprocal links cancel each other out from a search engines point of view but what counts as a recpirical link.

Do reciprocal links work on a site level or an individual page level?

If you where to say get an inbound link from site-a.com to mysite.com and then linked back from blog.yoursite.com would that be reciprical.

I'm aware Google sees subdomains as different domains all together but in this instance is that the same?

Answer 1

1. Site level (otherwise reciprocal link pages wouldn't count as reciprocal links since no trades links for the reciprocal link page. They do it for their home pages.)
2. Subdomains are not seen as separate domains