I'm a network engineer at an ISP and it's pretty common to use something like this for analyzing traffic network when considering peering sessions, for example. Even if you don't run BGP, you could use it for answering questions like "how much traffic do we send to/receive from Facebook?" and such.

RIPE's RIS dumps are performed every five minutes from more than a dozen different "vantage points" across the Internet.

ARIN used to provide an "originAS" file [1] but it looks like they quit doing that a few years ago. You may be able to find some interesting stuff browsing around /pub on their FTP server, though [2].

[0]: https://www.ripe.net/analyse/internet-measurements/routing-i...

[1]: ftp://ftp.arin.net/pub/originAS/

[2]: ftp://ftp.arin.net/pub/

https://iptoasn.com/ https://pypi.python.org/pypi/pyasn

I've been working on tweaking pyasn a bit and building a service around that.

    $ curl ipinfo.io/8.8.8.8
    {
      "ip": "8.8.8.8",
      "hostname": "google-public-dns-a.google.com",
      "city": "Mountain View",
      "region": "California",
      "country": "US",
      "loc": "37.3860,-122.0840",
      "org": "AS15169 Google Inc.",
      "postal": "94035",
      "phone": "650"
    }

    $ curl ipinfo.io/8.8.8.8/org
    AS15169 Google Inc.

Also, it's not clear what they're (ipinfo.io) using as their source for the ASN. Are they simply reporting the ASN as provided by ARIN, etc., or are they actually running BGP and reporting the origin ASN as they see it in announcements. My money would be on the former, in which case any prefix hijacking would not affect the data reported by ipinfo.io.

Regardless, if you want it, that data is available from the RIRs. Go crazy.

There's often a disconnect between something like that which works for one address, and something I could actually use to do bulk lookups on 5,000,000 addresses to generate reports.