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On Thu, 2006-10-12 at 22:42 -0400, Michael C. Toren wrote:
> On Thu, Oct 12, 2006 at 08:28:50PM -0400, Toby DiPasquale wrote:
> > UPenn owns 5 /16's. I don't know what they all are, but I know they own
> > 5 of them.
>
> It's easy enough to determine by peeking at the BGP announcements.
> First, find a single IP address the network in question is announcing,
> for example by querying DNS for the IP address of a primary MX:
>
> [mct@ellesmere ~]$ mx upenn.edu
> upenn.edu mail is handled by 0 nisc.net.isc.upenn.edu.
>
> [mct@ellesmere ~]$ host nisc.net.isc.upenn.edu.
> nisc.net.isc.upenn.edu has address 128.91.2.210
>
> Next, determine which ASN is announcing a BGP route covering that address,
> by logging into a public route server:
>
> route-server.savvis.net>sh ip bgp 128.91.2.210
> BGP routing table entry for 128.91.0.0/16, version 136280
> Paths: (1 available, best #1)
> Not advertised to any peer
> 209 55, (aggregated by 55 192.84.2.254)
> 208.172.146.30 from 208.172.146.30 (208.174.15.163)
> Origin IGP, localpref 100, valid, internal
> Originator: 208.174.15.163, Cluster list: 208.172.146.29
>
> The fifth line of the above indicates that this IP address is announced by
> AS55, and whois confirms that this ASN is registered to upenn.edu. Now,
> it's as simple as searching for routes which are announced by that ASN:
>
> route-server.savvis.net>sh ip bgp regex _55$
> [...]
> Network Next Hop Metric LocPrf Weight Path
> *>i128.91.0.0 208.172.146.30 100 0 209 55 i
> *>i130.91.0.0 208.172.146.30 100 0 209 55 i
> *>i158.130.0.0/17 208.172.146.30 100 0 209 55 i
> *>i158.130.128.0/17 208.172.146.30 100 0 209 55 i
> *>i165.123.0.0 208.172.146.30 100 0 209 55 i
> *>i192.84.2.0 208.172.146.30 100 0 209 55 i
>
> So, as of the time of this writing they're announcing four /16s and
> one /24.
>
> > I'll bet other schools have some, too (e.g. MIT, Stanford, etc).
>
> MIT was fortunate enough to have legacy Class A space, 18/8 :-)
>
> -mct
> ___________________________________________________________________________
> Philadelphia Linux Users Group -- http://www.phillylinux.org
> Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
> General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
Thanks for this quick little tutorial. Appreciated.
--
Regards,
Principal Engineer
Qlogic Corporation
O:610-233-4870
C:267-242-9306
___________________________________________________________________________
Philadelphia Linux Users Group -- http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
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