With regard to using a subdomain such as blog.mydomain.com for SEO purposes, it has been my understanding that IBLs from pages and websites that are on the same host or within the same class D network are not weighed as heavily since they are "local" to the domain.

Take the following example:

www.mydomain.com is hosted on 111.222.111.222
blog.mydomain.com is hosted on 111.222.111.223 (same class D network (or IP block))

www. is hosted on 111.222.111.222
blog. is hosted on 238.254.182.69 (completely different IP block)

Would the second set of inbound links from blog.* hold a higher "IBL value" so-to-speak as opposed to the first blog link which is hosted in the same ip address block?

The reason for this is that inbound links from external domains that are hosted completely outside of the domain in question are considered to be more "authentic" due to the fact that I could create any page on my current host that is just full of junk keywords.

This is just what I've heard (or read, as the case may be). I'm by no means an SEO expert, so let me know if you agree or disagree with the statements above.

Rick
All in General Outdoors
http://all-in-general.com