If ARIN (https://www.arin.net) is in charge of assigning IP addresses to individuals and organizations (in America) in order to avoid IP address conflicts on the internet, why do they not publish an Autonomous System Number (ASN) that the IP address is assigned to? If they do, where is it located?
If they don't publish it, how are routers supposed to know who's right (I'm aware of http://www.irr.net, but I don't know where they derive their authority from.)?
I've done quite a bit of reading on this topic and it seems like the simple answer is, it is a problem. ARIN assigns IP addresses and AS numbers to organizations, but doesn't assign assign IP addresses to AS numbers. It seems as though the organization is free to do whatever they want, even allow another organization use the IP address in their AS, or use it in any AS number assigned to the organization that the IP address belongs to. How to verify authenticity of permission of an IP to be used by an AS, and the AS itself is the problem.
RPKI is one attempt to improve the situation, but its adoption is still very low.
I'm guessing ARIN and the other RIR don't want to get involved in publishing IP to ASN number mappings because it's a lot of data and they don't want to be in the business of serving and managing all that data. I think RPKI allows some of the data to be distributed, in a hierarchical manner similar to DNS, therefor making the system more scalable.
ARIN does track/publish which AS an IP block belongs to. See this page for example which shows that the net range of 75.64.0.0 - 75.75.191.255 is originated from AS7922 (Comcast).
