From: Tomas L. Byrnes (no email)
Date: Sat Feb 02 2008 - 15:39:22 EST
You could achieve the exact same result simply by not advertising the
network to your peers, or by advertising a bogus route (prefixing a
known bogon AS for the addresses you want null-routed). I realize you
would have to subnet/deaggregate your netblocks, and therefore could
wind up with a prefix-length issue for peers who won't accept routes
longer than a certain mask, in some cases, but if you are already being
DDOSed, this should represent SOME improvement.
If you're trying to do it on a /32 basis, I doubt you'd find too many
border router operators interested in accepting a route that small, but
I may be wrong.
The bigger issue with all these approaches is that they run afoul of a
patent applied for by AT&T:
http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u
=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=200
60031575&OS=20060031575&RS=20060031575
USPTO App Number 20060031575
> -----Original Message-----
> From: [mailto:] On
> Behalf Of Ben Butler
> Sent: Saturday, February 02, 2008 12:17 PM
> To: Paul Vixie;
> Subject: RE: Blackholes and IXs and Completing the Attack.
>
>
> Hi,
>
> I was not proposing he Null routing of the attack source in
> the other ISPs network but the destination in my network
> being Null routed as a destination from your network out.
>
> This has no danger to the other network as it is my network
> that is going to be my IP space that is blackholed in your
> network, and the space blackholed is going to be an address
> that is being knocked of the air anyway under DoS and we are
> trying to minimise collateral damage. I cant see where the
> risk to the large NSP is - given that the route reflector
> will only reflect /32s that legitimately originate (as a
> destination not a source) in the AS announcing them as please
> blackhole.
>
> For complete clarity: AS13005 announces 213.170.128.0/19 and
> has its route object in RIPE as being announced by AS13005.
> My router at IX - BENIX say - announces 213.170.128.1/32 to
> the router reflector their, the announcement from my IX
> assigned address 212.121.34.30 is known to be my router on
> the exchange, and I am announcing a /32 from my AS for a
> route object registered as being announced by my AS - so the
> reflector accepts my announcement and reflects it to any
> other members that choose to peer with this reflector -
> effectively this is a please blackhole this destination in
> AS13005 - the other members that receive this announcement
> can then deal with it in anyway they see fit from ignoring it
> to setting next-hop 192.0.2.1 -> Null0.
>
> The effect of this would be that any BotNet controlled hosts
> in the other member network would now be able to drop any
> attack traffic in their network on destination at their
> customer aggregation routers.
>
> I think you might have thought I was suggesting we blackhole
> sources in other peoples networks - this is definatly not
> what I was saying.
>
> So, given we all now understand each other - why is no one
> doing the above?
>
> At the end of the day if an IX member doesn't want the
> announcements don't peer with the blackhole reflector,
> simple, and it will get Null routed as soon as it hits my
> edge router at the IX - it would just seem more sensible to
> enable people to block the traffic before it traverses the IX
> and further back in their own networks.
>
> So?????
>
> Ben
>
>
>
> -----Original Message-----
> From: [mailto:] On
> Behalf Of Paul Vixie
> Sent: 02 February 2008 17:32
> To:
> Subject: Re: Blackholes and IXs and Completing the Attack.
>
>
> ("Ben Butler") writes:
>
> > ...
> > This hopefully will ensure a relatively protected router
> that is only
> > accessible from the edge routers we want and also secured to only
> > accept filtered announcements for black holing and in consequence
> > enable the system to be trusted similar to Team Cymaru.
> > ...
>
> This sounds like another attempt to separate the Internet's
> control plane from its data plane, and most such attempts do
> succeed and are helpful (like NSP OOB, or like
> enterprise-level anycast of DNS).
> However, I'm not sure that remote triggered blackholes are a
> good direction, worthy of the protection you're proposing,
> for three reasons.
>
> First, because large NSP's simply cannot afford the risk
> associated with letting a third party, automatically and
> without controls or audits, decide in real time what sources
> or destinations shall become unreachable. With all respect
> (which is a lot) for spamhaus and cymru and even MAPS (which
> I had a hand in, back in the day), feeding BGP null-routes to
> a multinational backbone is a privilege that ISO9000 and
> SarBox and liability insurance providers don't usually want to extend.
>
> Second, because many backbone routers in use today can't do
> policy routing routing (which is in this case dropping
> packets because their source address, not their destination
> address, has a particular community associated with it) at
> line speed. Note, this is many-not-all
> -- I'm perfectly aware that lots of backbone routers can do
> this but not everybody has them or can afford them and those
> who have them tend to be the multinational NSPs discussed earlier.
> To prevent our DDoS protection reflexes from lowering an
> attacker's cost (by automatically blackholing victims to
> protect the nonvictims), we have to be able to blackhole the
> abusive traffic by source, not by destination.
>
> Third, because many OPNs (other people's networks) still
> don't filter on source address on their customer-facing edge,
> and thus allow spoofed-source traffic to exit toward "the
> core" or toward a victim's NSP who cannot filter by source
> due to path ambiguities inherent in "the core", any wide
> scale implementation of this, even if we could get trusted
> automation of it at scale and even if everybody had
> policy-routing-at-like-speed, would just push the attackers
> toward spoofed-source. That means a huge amount of work and
> money for the world, without changing the endgame for
> attackers and victims at all.
> (See BCP38 and SAC004 for prior rants on this controversial topic.)
>
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