I need to identify all IP addresses assigned to a specific ASN (Autonomous System Number) at specific points in time in the past. Is it standard practice to reasign IP addresses from one ASN to another? If so, how do I get historical data on these allocations. I believe I can get them by looking through the archives of each RIR individually. For example, here is what it looked like on Jan 1, 2015 for ARIN:
ftp://ftp.arin.net/pub/stats/arin/delegated-arin-extended-20150101
Unfortunately, it looks like before mid 2013, they don't include links between ASNs and IPv4. It seems like I might be able to do something like using whois.cymru.com:
http://www.team-cymru.org/IP-ASN-mapping.html
However, it's not obvious to me exactly what is meant by the date and time in this query:
whois -h whois.cymru.com " -v 216.90.108.31 2005-12-25 13:23:01 GMT"
AS | IP | BGP Prefix | CC | Registry | Allocated | Info | AS Name
23028 | 216.90.108.31 | 216.90.108.0/24 | US | arin | 1998-09-25 | 2005-12-25 13:23:01 GMT | TEAMCYMRU - SAUNET
Moreover, I really need to be able to go from ASN to BGP/IP and not the reverse. Note that I can do all of this very easily using current data from maxmind.com but I need historical data on these IP assignements.
