Re: well-known Anycast prefixes

[Bill Woodcock <woody () pch net>]

I imagine that the “description” of each entry in the list should include a machine-readable field indicating the use. 

There was a question about the use-case... I’m sure a lot of people in the ops community have their own reasons related 
to routing and filtering and so forth, but there’s also a huge demand for this kind of information, aggregated and 
sanity-checked, to support academic research at the graduate level. And the better we support those kids with 
real-world data, the more practical an education they receive, and the more ready they are to jump in to jobs we offer 
them in industry when they graduate. Supporting kids and networking graduate programs like that is a big part of our 
work, that tends not to be visible on the operations side. 

Academics downloaded routing-archive snapshots from us nearly 300 million times, last year, for example. 
    
                -Bill


> On Mar 21, 2019, at 09:52, Ross Tajvar <ross () tajvar io> wrote:
>
> Not all any-casted prefixes are DNS resolvers and not all DNS resolvers are anycasted. It sounds like you would be 
> better served by a list of well-known DNS resolvers.
>
> > On Thu, Mar 21, 2019 at 12:35 PM Bryan Holloway <bryan () shout net> wrote:
> >
> > On 3/21/19 10:59 AM, Frank Habicht wrote:
> > > Hi James,
> > >
> > > On 20/03/2019 21:05, James Shank wrote:
> > > > I'm not clear on the use cases, though.  What are the imagined use cases?
> > > >
> > > > It might make sense to solve 'a method to request hot potato routing'
> > > > as a separate problem.  (Along the lines of Damian's point.)
> > >
> > > my personal reason/motivation is this:
> > > Years ago I noticed that my traffic to the "I" DNS root server was
> > > traversing 4 continents. That's from Tanzania, East Africa.
> > > Not having a local instance (back then), we naturally sent the traffic
> > > to an upstream. That upstream happens to be in that club of those who
> > > don't have transit providers (which probably doesn't really matter, but
> > > means a "global" network).
> >
> > /snip
> >
> > > Greetings,
> > > Frank
> >
> > I can think of another ...
> >
> > We rate-limit DNS from unknown quantities for reasons that should be 
> > obvious. We white-list traffic from known trusted (anycast) ones to 
> > prevent a DDoS attack from throttling legitimate queries. This would be 
> > a useful way to help auto-generate those ACLs.