I think Level(3) uses it for at least some L3 MPLS VPN stuff. We peer with that AS for dedicated SIP service transport for example.
On Aug 8, 2013, at 5:25 AM, Humberto Galiza <humbertogal...@gmail.com> wrote: > Looking at our routers I can see this: > 3549 3356 26114 1 i > 12956 1239 23520 23383 1 ? > > but neither 26114 or 23383 are Brazilian ISP´s. Anyway, I guess it´s > probably leaked routes or even use of AS 1 as private one (I don´t > think level3 guys are using this AS anymore...). > > Cheers, > Humberto Galiza > > > 2013/8/4 Anurag Bhatia <m...@anuragbhatia.com>: >> Hello everyone >> >> >> I was looking at global IPv4 table and saw some strange entries from AS1. >> As per ARIN whois AS1 seems to be with Level3 but I noticed few prefixes of >> Brazil based ISP - Netvip >> >> >> http://bgp.he.net/AS1#_prefixes >> >> >> >> Looking at any prefix in detail, it seems like there are multiple ASNs >> announcing same prefix. >> >> E.g 177.185.96.0/24 - is being announced by AS1 as well as AS52931 >> (Netvip's allocated ASN). Same is true with 177.185.98.0/24, >> 177.185.98.0/24and so on. >> http://bgp.he.net/net/177.185.96.0/24 >> >> So seems like AS1 acting like a mirror for all announcements of AS52931. To >> see who exactly gave "transit" to AS1 by Netvip in Brazil, I checked Oregon >> and noticed these routes: >> >> 3356 3549 16735 52931 1 i >> >> >> >> Seems like AS52931 itself is acting as transit for AS1 (and AS16735 which >> seems like a backbone ISP in Brazil) is not filtering these routes further >> passing to Level3 (AS3549+AS3356). >> >> >> >> I am curious to know what could be possible reason for an ASN like AS1 >> acting in exact mirror of AS52931? Could it be a case of internal use of >> AS1 (assuming it to be private ASN)? May be it's a case of leaked internal >> routes? >> >> >> >> Appreciate your time & answer. >> >> >> >> Thanks. >> >> -- >> >> Anurag Bhatia >> anuragbhatia.com >> >> Linkedin <http://in.linkedin.com/in/anuragbhatia21> | >> Twitter<https://twitter.com/anurag_bhatia> >> Skype: anuragbhatia.com >
