[c-nsp] Which IP's belong to AS1234?

[Gert Doering]

Hi,

On Fri, Sep 25, 2009 at 04:55:48PM +1000, Andy Saykao wrote:
> This might be a silly question but is there a tool somewhere that will
> give me a list of IP's that are owned by a particular AS.
>  
> As an example, I might want to know which IP blocks belong to AS1234?

What exactly do you mean with "belong"?

Besides the fact that IP addresses are not property, even so, different
ways to look at that question will give different answers:

 - provided by a registry (RIPE, ARIN, etc.) to the company also holding
   AS1234 (and maybe other ASes)

 - announced by AS1234 (but that could as well be customer networks)

The first question is fairly difficult to answer.  The second can be 
answered by checking the BGP tables, e.g. on route-views.oregon-ix.net

$ telnet route-views.oregon-ix.net
...
route-views.oregon-ix.net>sh ip b reg _1234$
...
   Network          Next Hop            Metric LocPrf Weight Path
*  193.110.32.0/21  194.85.4.55                            0 3277 3216 6667 1234 1234 1234 1234 i


gert
-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
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