[dns-operations] Looking for a public blackhole/sinkhole IP address
warren at kumari.net
Thu Nov 27 15:38:35 UTC 2014
On Wed, Nov 26, 2014 at 7:12 PM, Robert Edmonds <edmonds at mycre.ws> wrote:
> Warren Kumari wrote:
>> This thingie has many aspects that look a bunch like AS112 -- I'm
>> wondering if it makes sense to also request an AS number for this.
>> It's not strictly needed, but having fewer inconsistent origin routes
>> is always nice.
>> It also seems that (also like AS112), networks could do this in one of
>> (at least) 3 ways:
>> 1: They can spin up this route purely within their own network --
>> basically have one or more places where the route points at null0 /
>> discard and *not announce it to peers / customers* or
>> 2: announce to customers only or
>> 3: be good citizens and announce it to everyone.
>> 1 and 2 already exist, for RTBH (like you mention in the doc), they
>> are just not anycasted. I wonder if we ask the IANA nicely if they'd
>> assign 666.666.666.0/24 to.. oh, bugger....
>> The more people who do this, the more benefit there is - unfortunately
>> this argument often doesn't work on the Internets, but still worth
> If one is trying to dispose of "250 million DNS requests per second" 
> or "> 1Mr/s (mega-requests per second)" , then you probably *don't*
> want the traffic to be routed to whoever happens to have announced it,
> or anywhere, really.
Yes -- which is why many (most?) networks already have a RTBH
destination / null route. If you are at the receiving end of  or
, you sure don't want to be routing this back out to a community
blackhole, you want to drop it as soon as possible instead[*]. This
means shuffling it off to something that can drop it ASAP, like as
soon as you touch it -- you'll probably send this to a discard route
(forwarding > filtering) -- in which case you A: route it to your
already existing discard prefix, in which case why not use the address
we are requesting for this? or B: you realize you really should have a
discard prefix -- in which case, why not spin up the prefix we are
> That seems to be a much different use case (drop
> the traffic as quickly and universally as possible, minimizing
> collateral damage) from routing the traffic to something like a
> community sinkhole.
Yes -- and the whole point of this plan would provide the "as quickly
and universally as possible". The theory (hope) is that *most* people
will spin up this prefix and null route it, preferably on their edges.
Perhaps "community sinkhole^Wblackhole" is the wrong term / conjures
up the wrong image, and "universal blackhole" would be better.
What we are aiming for / proposing is a "toss this as soon as
possible", not "route to a small number of sinkholes run by some
volunteers". The incentive model here is that, the more people who do
this, the more useful it is -- and so, one day when *I* need it, it
will be available. This might suffer from a tragedy of the commons
type problem - I'll just hope that other folk do it, so I don't need
to sink the badness. One nice property that this has versus something
like BGP38 / SAVE is that it is very easy to tell if your peers are
not doing it -- and so you could easily include it in peering /
What would be really nice (IMO) is, if we get consensus on this, to
recommend that router's do this automagically (with a turn off knob) -
there are already a number of "special" prefixes that some devices
handle (127/8, 169.254.0.0/16, 240/4, etc) - having a default <this
prefix>/24 -> discard in devices would make it so that the very first
devices seeing the traffic would dump it.
[*]: Actually, it's unclear if this would have worked for  and 
- you might need some more granularity than "Aaargh, make this stop!"
>  http://www.forbes.com/sites/parmyolson/2014/11/20/the-largest-cyber-attack-in-history-has-been-hitting-hong-kong-sites/
>  https://la51.icann.org/en/schedule/mon-tech/presentation-dafa888-dos-attack-13oct14-en.pdf
> Robert Edmonds
> dns-operations mailing list
> dns-operations at lists.dns-oarc.net
> dns-jobs mailing list
I don't think the execution is relevant when it was obviously a bad
idea in the first place.
This is like putting rabid weasels in your pants, and later expressing
regret at having chosen those particular rabid weasels and that pair
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