nanog mailing list archives
Re: Strange entries from AS1 in global table
From: Brad Fleming <bdflemin () gmail com>
Date: Thu, 8 Aug 2013 09:48:46 -0500
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 <humbertogaliza () 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 <me () 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
Current thread:
- Strange entries from AS1 in global table Anurag Bhatia (Aug 03)
- Re: Strange entries from AS1 in global table Humberto Galiza (Aug 08)
- RE: Strange entries from AS1 in global table Vinny_Abello (Aug 08)
- Re: Strange entries from AS1 in global table Brad Fleming (Aug 08)
- RE: Strange entries from AS1 in global table James Sink (Aug 08)
- Re: Strange entries from AS1 in global table Humberto Galiza (Aug 08)