IP to authoritative CIDR webservices

William Pitcock nenolod at systeminplace.net
Mon Dec 14 23:18:23 CST 2009


Hi,

On Mon, 2009-12-14 at 21:12 -0800, Paul Ferguson wrote:
> On Mon, Dec 14, 2009 at 8:57 PM, William Pitcock
> <nenolod at systeminplace.net> wrote:
> 
> > Hi,
> >
> > Does anyone know of a webservice that converts a given IP into the
> > public CIDR range that belongs to?  I am developing a tool where IP to
> > CIDR conversion based on RIR whois data would be useful for implementing
> > filtersets.
> >
> 
> WHOIS?
> 
> Alternatively, use the Team Cymru tool to find the AS, then the CIDR Report
> portal to determine all perfixes originated by the AS in question:
> 
> http://asn.cymru.com/

Looks like their WHOIS server in verbose mode will do the trick for what
I want, as it provides predictable output.  Thank you.

William






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