I'm really confused. I have a list of all the AS numbers and their "description", which I got from MaxMind. I thought the ASN system was pretty straightforward, but let me show you my confusion.
Take AS30058 for example, belonging to FDC Servers: http://bgp.he.net/AS30058. So you would assume that that is the complete list of IPs controlled by that company.
But now look at the huge AS1744, belonging to Congent Communications: http://bgp.he.net/AS174#_prefixes ... there are many many ranges defined there, with the description "FDCservers.net" there too, that were not part of AS30058. So we can assume that they belong to FDCservers.net too, right?
Could it be the case that these ranges were handed back to the ISP/owner/whatever, and their info just has not been updated as they have not been re-used yet?
Also note that if you click on one of those IP ranges,
So, can someone explain the reasoning behind this sort of thing? What is the point of that? Also, is there a way for me to find out all possible IP ranges that belong to a company like FDCservers.net, or some sort of whois query?
I am just trying to get a better understanding of how all this works.