Re: [sidr] [Idr] AS_SET depreciation (RFC6472) and BGP multipath
heasley <heas@shrubbery.net> Wed, 28 March 2012 17:30 UTC
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Date: Wed, 28 Mar 2012 17:30:10 +0000
From: heasley <heas@shrubbery.net>
To: "Murphy, Sandra" <Sandra.Murphy@sparta.com>
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References: <alpine.LFD.2.02.1203281401410.2692@jamaica.dcs.gla.ac.uk> <7309FCBCAE981B43ABBE69B31C8D21391B3EBFD895@EUSAACMS0701.eamcs.ericsson.se> <FBFDBAE5-9BF8-4708-9240-B775CAF46D56@raszuk.net> <7309FCBCAE981B43ABBE69B31C8D21391B3EBFD924@EUSAACMS0701.eamcs.ericsson.se> <alpine.LFD.2.02.1203281618090.2692@jamaica.dcs.gla.ac.uk> <CAL9jLaYqMwXVNKsHuBf_r8h==CGoee+D9k89Q4AZqT49jOQK1A@mail.gmail.com> <4F733C79.8080600@raszuk.net> <CAL9jLabVcWMtpu8usUS5w_BVPCG8ihvDcVjWbhnj_u6H-cdZkw@mail.gmail.com> <4F733FBE.1020902@raszuk.net> <24B20D14B2CD29478C8D5D6E9CBB29F60F6CB73F@Hermes.columbia.ads.sparta.com>
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Cc: "idr@ietf.org List" <idr@ietf.org>, Paul Jakma <paul@jakma.org>, sidr wg list <sidr@ietf.org>
Subject: Re: [sidr] [Idr] AS_SET depreciation (RFC6472) and BGP multipath
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Wed, Mar 28, 2012 at 05:00:43PM +0000, Murphy, Sandra: > Replacing ASs in the AS_PATH sounds like a behavior you would want the security protections to prohibit. It would enable attacks. > > Can you explain how you would distinguish legitimate uses of this feature? I've not used this feature, but from cisco's documentation, it doesnt appear to function as raszuk described. http://www.cisco.com/en/US/docs/ios/12_3t/12_3t11/feature/guide/gtbgpdas.html if local-as is configured for a peer(-group), ie: if configured to peer as a different AS than your own, such as for merging two ASes or changing your ASN, then: "The replace-as keyword is used to prepend only the local autonomous-system number (as configured with the ip-address argument) to the AS_PATH attribute. The autonomous-system number from the local BGP routing process is not prepended." though I think that is unclear, I interpret it to mean that if my ASN is 1 and, I peer as ASN 2 with ebgp peer 3, then a route received from AS 3 will have the path [2 3], but if configured with replace-as, it will be [3]. I do not believe that the feature allows the arbitrary replacement of AS path elements. > --Sandy > > ________________________________________ > From: sidr-bounces@ietf.org [sidr-bounces@ietf.org] on behalf of Robert Raszuk [robert@raszuk.net] > Sent: Wednesday, March 28, 2012 12:43 PM > To: Christopher Morrow > Cc: idr@ietf.org List; Paul Jakma; sidr wg list > Subject: Re: [sidr] [Idr] AS_SET depreciation (RFC6472) and BGP multipath > > >> Are we going to freeze any AS_PATH modifications by operator's policy too ? > >> I mentioned replace-as which all major vendors support. There can be more > >> knobs like this coming in the future. > > > > replace as i think is dealt with .... sign again and pcount=0 and move along. > > replace-as allows to replace any arbitrary match of list of ASes in the > AS_PATH by your own AS. Does not need to be the last one. > > I don't think SIDR has a solution to deal with such policy. > > Best regards, > R. > _______________________________________________ > sidr mailing list > sidr@ietf.org > https://www.ietf.org/mailman/listinfo/sidr > _______________________________________________ > sidr mailing list > sidr@ietf.org > https://www.ietf.org/mailman/listinfo/sidr
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jakob Heitz
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Paul Jakma
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jakob Heitz
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Robert Raszuk
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jakob Heitz
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Paul Jakma
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Christopher Morrow
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Robert Raszuk
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Christopher Morrow
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Robert Raszuk
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jeffrey Haas
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Christopher Morrow
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Murphy, Sandra
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… heasley
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jakob Heitz
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Robert Raszuk
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Robert Raszuk
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Brian Dickson
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Robert Raszuk
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jeffrey Haas
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jeffrey Haas
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jeffrey Haas
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Christopher Morrow
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jakob Heitz
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Jeffrey Haas
- Re: [sidr] [Idr] AS_SET depreciation (RFC6472) an… Susan Hares