-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Steven M. Bellovin schrieb:
On Fri, 13 Feb 2009 16:41:41 +0000 (WET) Nuno Vieira - nfsi telecom <nuno.vieira@nfsi.pt> wrote:
Ok, however, what i am talking about is a competelly diferent thing, and i think that my thoughts are alligned with Jens.
We want to have a Sink-BGP-BL, based on Destination.
Imagine, i as an ISP, host a particular server that is getting nn Gbps of DDoS attack. I null route it, and start advertising a /32 to my upstream providers with a community attached, for them to null route it at their network. However, the attacks continue going, on and on, often flooding internet exchange connections and so.
A solution like this, widelly used, would prevent packets to leave their home network, mitigating with effective any kind of DDoS (or packet flooding).
Obviously, we need a few people to build this (A Website, an organization), where when a new ISP connects is added to the system, a prefix list should be implemented, preventing that ISP to announce IP addresses that DON'T belong to him.
The Sink-BGP-BL sends a full feed of what it gots to Member ISP's, and those member ISP's, should apply route-maps or whatever they want, but, in the end they want to discard the traffic to those prefixes (ex: Null0 or /dev/null).
This is a matter or getting enough people to kick this off, to build a website, to establish one or two route-servers and to give use to.
Once again, i am interested on this, if others are aswell, let know. This should be a community-driven project.
In other words, a legitimate prefix hijacking service...
As Randy and Valdis have pointed out, if this isn't done very carefully it's an open invitation to a new, very effective DoS technique. You can't do this without authoritative knowledge of exactly who owns any prefix; you also have to be able to authenticate the request to blackhole it. Those two points are *hard*.
As described in my earlier mail, I'd suggest to run a prefix-list generator updating informations from IRR on a regulary basis and, as soon as a new "matching" route-object appears in IRR, an automated mail might be send to the ASN-owner (address also taken from irr-records) with a confirmation-link. That way you'd need to hijack IRR-database and/or tech-c/admin-c mailbox before being able to have a prefix added to the list of prefixes accepted from your peer.
I also note that the scheme as described here is incompatible with more or less any possible secured BGP, since by definition it involves an AS that doesn't own a prefix advertising a route to it.
No, the router may work as Route-Reflector, so you see exactly the as-path as is and the route-reflectors own asn isn't visible at all..
--Steve Bellovin, http://www.cs.columbia.edu/~smb
- -- =================================================================== Jens Ott Leiter Network Management Tel: +49 22 33 - 612 - 3501 Fax: +49 22 33 - 612 - 53501 E-Mail: j.ott@plusserver.de GPG-Fingerprint: 808A EADF C476 FABE 2366 8402 31FD 328C C2CA 7D7A PlusServer AG Daimlerstraße 9-11 50354 Hürth Germany HRB 58428 / Amtsgericht Köln, USt-ID DE216 740 823 Vorstand: Jochen Berger, Frank Gross, Jan Osthues, Thomas Strohe Aufsichtsratsvorsitz: Claudius Schmalschläger =================================================================== -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkmVre4ACgkQMf0yjMLKfXp2oQCfS3/zTUAgjN0VegvctemS+NL6 +v0AnivXszJ0extA/mspFakX7MR3w+Y6 =gu7J -----END PGP SIGNATURE-----