IP Prefixes are allocated ..

william(at)elan.net william at elan.net
Mon Nov 28 07:13:33 UTC 2005



On Mon, 28 Nov 2005, Glen Kent wrote:

> to different Autonomous systems.
>
> Is there a central/distributed database somewhere that can tell me
> that this particular IP prefix (say x.y.z.w) has been given to foo AS
> number?

IP prefixes are not "given" to AS numbers. They are assigned & allocated 
to organizations that can choose to announce it themselves (in which
case you may search for ASN name with same organization name as who 
the ip block is is assigned to) or have their ISP announce it (in this
case ISPs often register ip block in RR - may appear in whois.radb.net).

> I tried searching through all the WHOIS records for a domain name. I
> get the IP address but i dont get the AS number.
> Any clues on how i can get the AS number?

I suspect what you're really asking is who is announcing a particular
ip address in BGP. If you want to do it by whois, I recommend this:

  whois -h riswhois.ripe.net <ip-address>

-- 
William Leibzon
Elan Networks
william at elan.net



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