[6126] in North American Network Operators' Group
Re: Mapping IP -> ASN
daemon@ATHENA.MIT.EDU (Alex.Bligh)
Fri Nov 15 12:52:38 1996
To: lyndon@esys.ca
cc: nanog@merit.edu
In-reply-to: Your message of "Fri, 15 Nov 1996 10:02:10 MST."
<SIMEON.9611151010.A15165@cezanne.esys.ca>
Date: Fri, 15 Nov 1996 17:30:38 +0000
From: "Alex.Bligh" <amb@xara.net>
> Is there a tool available that will take an IP address and return the
> ASN attached to that network? I've been in situations before where this
> information would be useful, but not having access to the BGP routing
> information I'm not sure how to do this? (I've looked around some
> "likely" web sites - such as Merit - but haven't found anything.)
>
> The pressing need is for the ASN associated with 198.161.92.0. This
> network is connected to I*star, but I can't tell which of I*star's
> three ASNs it's homed on. (And they aren't being responsive to queries.)
Practical:
Use show ip b n.n.n.n or equivalent on something carrying full routing.
If you don't have anything carrying full routing do the equivalent on
Digex's excellent MAE-East looking glass at http://nitrous.digex.net,
or the cern router.
Theoretical:
Alternatively find out which AS it's meant to be originated in by
looking at the origin attribute in the appropriate IRR using whois
(assuming it's registered).
Alex Bligh
Xara Networks
