Do any important SEO robots (such as search engine crawlers) rely on IP addresses anymore to identify websites?

Question

Currently, I have it where anyone who attempts to access my server IP address as a website (example: http://nnn.nnn.nnn.nnn) will be redirected to a domain name with the original request URI appended. For example, http://nnn.nnn.nnn.nnn/test will be redirected to http://example.com/test

The last time I ran the seo tool at seositecheckup.com on my site, it mentions that I should have the IP address redirect to the domain as explained above.

The following URL also suggests the same:

http://techglimpse.com/fix-improve-site-seo-ip-canonicalization/

From a performance point of view, I feel I could make any request beginning with http://nnn.nnn.nnn.nnn return only errors and not log any of them, but the question is, are there any important SEO robots out there (such as any web crawlers in the world) that require scanning a website by IP address?

Answer 1

When a crawler reads a website it reads the IP as the domain is just a human readable version of the IP thanks to DNS

But to answer your question no I don't believe it matters as 20 websites sharing an IP on shared hosting will not be treated less important than say a single website hosted on a dedicated IP

Although the shared vs dedicated IP debate is quite a hostile one and out of scope for this question. It gets quite uncomfortable actually.