Re: [ncc-services-wg] New service: ip2asn
- Date: Fri, 26 Sep 2003 17:51:23 -0700 (PDT)
#3) "Routeviews project now has a test/static asn zone up that you can try"
# % dig @archive.routeviews.org 18.104.22.168.asn.routeviews.org txt
# comments: interesting idea but at the time it was still under
It's a production service now, and gets rebuilt and reloaded twice a day;
DMM announced it on NANOG, for example.
The comment was also offered:
# strange replies on non-matched IPs, e.g. try
# host -t txt 7.227.290.195.asn.routeviews.org
Zen-like question: for dotted quads not in the routing table, what *should*
be returned? One postulated answer: 4294967295 ==> "route not in table"
You could pick some other "magic" number, but I think this one should serve
the purpose just fine. :-)
Regarding the other ip2asn methods, I'm happy having a thousand methods
bloom, so long as they enhance the ability of folks to tie dotted quads to a
relevant responsible entity. :-)
P.S. Also note that in addition to the asn zone, an aspath zone is also
available, provided in part to deal with any attempt to interpose
"throw away" stub ASNs to shelter "real" ASNs; it is available by querying
host -t txt $revip.aspath.routeviews.org
Be sure to anticipate and plan for the possibility of multiple aspath txt
records being returned in response to a query.