[dns-operations] Slow Drip DDOS Attack Research

[Stephane Bortzmeyer]

On Wed, Nov 07, 2018 at 09:58:55AM -0800,
 Paul Vixie <paul at redbarn.org> wrote 
 a message of 31 lines which said:

> i also question whether open resolvers are truly nec'y for this
> attack.  opendns and google do a lot of rate limiting and have 24x7
> human coverage to detect anomalies. i have to assume that IBM and
> CloudFlare do the same, or else we'd have heard about other
> amplification attacks through those open recursives before now.

OpenDNS and Google Public DNS are public resolvers (managed), not open
resolvers (unmanaged, and probably open by mistake). (RFC 7719,
section 5).